Hello my friend,
First of all releasing guilt/remorse can possibly take a lot of time (or not), so don't get discouraged too fast if you don't see yourself free from it as soon as you wished. But it is possible for it to get better or all together eliminated, no matter what you are having this feeling of guilt for. Your mind might be telling you now ''Yes, for everything, EXCEPT the one thing I am obsessing over''. And this might feel too real to ignore, like this is where we cross the line. But, please make this leap of faith for now. That leap of faith and a constant care for yourself is all you need, and I promise it can possibly get so much better to the point you completely let go of it. So please give yourself a hug and as much time you need to process this.
Having said that, here are some usefull tools you might want to use:
1) Take this as a chance to UNDERSTAND what went wrong. Not what went wrong in the narrow, particular instance that you are feeling guilty over, (although that could be useful, too). Take a look at your whole life. Imagine yourself as a blank slate and go through your years examining what happened to you or what you went through, what feelings you had that you struggled with growing up or as an adult, what behaviours you picked up from your environment, friends, culture etc. You might find particular traumatic instances or you might find extended periods of time that were traumatic, too, maybe in a less obvious way. Or you might find certain harmful behaviours or ways of thinking that were normalised by your immediate or cultural environment. No matter what you find, keep in mind that all these things shape us, and can manifest in behaviour that causes harm to others and ourselves. Understanding this can give you an insight to the process of how pain propagates itself (which you seem to already have). You hurt another person because you were hurt yourself in some way, in the past. Even if it's difficult at first to put the pieces together, that's the case. The event you are feeling guilty over is just one recent episode of a chain of pain, one that stretches back to the begining of your life and waaay beyond it. When we are unconscious of this chain, it can manifest in our behaviour. When we become concsious of it, it's a big step towards braking the chain.
2) Adopting responsibility. Responsibilty does not mean that you're gonna be wallowing in negative emotions for ever. That's not helping anyone, not you, not the other person, not anyone in the world. Responsibility means that you take time to see 1) exactly why your behaviour was harmful and 2) what hurt place inside you caused it, and commit to the best of your ability to 1) not repeat a similar behaviour that you have found to be harmful in the future and 2) to take deep care of the wounded place inside you that the behaviour manifested from. Apologising is a very good start but keeping up with the 2 aspects of responsibility is what matters in the end.
3) A note regarding ''wallowing in negative emotions forever'': In buddhism they say ''No dwelling on past mistakes'' and that's for a good reason. Dwelling on past mistakes in a way that only perpetuates and recycles self-contempt, as said above is not doing anyone any good, not you, not other people. So, make a distinction between pure, utter self-contempt on the one hand, and adopting responsibility (in the way described above) on the other. Do not confuse one for the other. The former is self-absorbed, problem-focused and unproductive. The latter is self-caring, focused on the solution and productive (maybe among the most trully productive, worthwhile things to do in life). So make a clear distiction, know one from the other, and choose the productive one. You may (or may not) feel that self-contempt is unavoidably part of the process. Give it space and sit with it if you need, but don't let it highjack the entirety of the process. Instead, use this distiction here, between productive and unproductive to anchor yourself back.
4) Make a distinction between guilt and shame. Guilt is, to a certain extend, a healthy emotion, when it is temporary and in an appropriate proportion to the actual harm done. It lets us know that something we did was potentially harmful and we should not repeat it. And that's coming already from a higher perspective inside us. Shame, on the other hand, is how we feel other people would react towards us, or think of us, when confronted with the fact of our particular past behaviour. Part of your post talks about feeling like a ''bad'' or ''evil'' person not being able to part-take in the ''good'' group of people anymore. This dichotomy between ''bad'' and ''good'', although it could be part of a healthy and temporary sense of guilt that will motivate you for positive change in the future, this ''bad''-''good'' split could be more driven by shame. It's useful to know the difference between the two because you treat each one of them with different tools. This video here is good and makes the distinction clear:
Shame Versus Guilt: Knowing the Difference and Healing from Both
By D.Mackler
5) Don't make a self image out of such a tiny fraction of your life. This event is one drop in the ocean of events that compile your life. When you let it go, it will seem as any other random event. You will still be able to see how it was harmful and how much you've learned from it and what things you changed because of it, but it won't send you down a guilt trip. You are so much more than that, even under a dualistic perspective, what you call your ''self'' is a vast collection of events. Identifying so much with one is not appropriate. It shows that there might be some healing work to be done, some energy stuck in the past, but, in the end, your life has been a series of events that maybe amount to attributes about you that probably in their overwhelming majority are ''good''! So don't let any one particular thing define you.
Similarly, watch how you talk to yourself about the thing that is currently troubling you. Make sure to use precise and neutral words. Words are powerful and carry a very heavy charge with them so make sure you're not causing more suffering to yourself just because you use heavy-loaded words. Also make a clear distinction between a harmful act and a harmful/''bad'' person. We tend to jump from one to the other very carelessly and inappropriately. It's much more precise and true to reality to talk about harmful acts than reducing a whole person to being ''bad''.
6) Meditation. It might sound like a dry piece of advice but there are at least two good reasons for it.
-There is this quote from stoicism saying: ''People suffer more in imagination than in reality''. Imagination here is synonymous to thought. Recognising thought as mere thought, and not reality, is a big step. We tend to react to thought way out of proportion to what it actually is, which is basically pixels on our mental screen, coming and going, without our complete, conscious involvement. Also thoughts are highly distorted representations of reality, so keeping that in mind can help not taking them too seriously. And also recognising that all past and all future are again pixels on your mental screen, can ground you to the present, to ''reality'' as oposed to ''imagination'', as in the terms of the quote. Learning to letting go of thoughts can go a long way. (There is this video from Leo I remember, named ''Grasping the illusory nature of Thought''. Maybe relevant.
-Second reason why meditation can be useful: There is this quality that meditators develop called equanimity. Equanimity is the ability to let whatever experience arises to do its thing without you getting in the middle with resistance. Meditation can help you untangle your experience and break it down to its components, which, in the case of difficult emotions, usually are: 1) a thinking component, self-talk or internal imagery, and 2)a feeling component, raw sensations in your chest/stomach/thoat/etc. Taking your attention from the thinking component and focusing it on the feeling component can help you develop this quality of just letting emotions be, or, as in the stoicism quote, staying with ''reality'' and dismissing an overindulgence in ''imagination''. Also watch Leo's video on processing difficult emotions where he talks about aiming to make yourslef a ''super-conductor'' of emotions. That's what equanimity is partly about. Getting slowly comfortable with disscomfort.
(There are probably more reasons why meditation could help. I'm just stating the ones that I'm most familiar with and can put into words the best. Just to mention briefly a few more, look into Shinzen Young videos, ''Taste of Purification'' and ''How intense emotions can be no problem''. Second one is related to equanimity, but also introduces the concept of ''Complete Experience'' which is similar to what Leo refers to as ''superconducting emotions''. I do not know how familiar with or eager about meditation you are, so I might be getting a bit too technical here, but make use of whatever clicks with you.)
7) Allow yourself to cry as much as you need. And I mean deep sobbing, not just the frustrated type of crying that can occasionally happen. If you have been through both, you know what I am talking about. There is a process in psychotherapy called grieving and it happens primarily through deep crying. I've been able to let go of a break-up, very briefly after it happened, just by letting myself cry deeply non-stop for 30-40 mins. Crying can be magical
maybe this video is useful. What he describes at 13:55 is a healing/sobbing experience, just for reference:
Grieving -- The Key to Healing Trauma by D.Mackler
8) Non-dual awakenings. A drop of emptiness can potentially be more healing than years of therapy. Take this with a grain of salt, depending on how familiar you are with this kinda stuff. Maybe there is more of hands-on, strictly emotional/therapy type of work to be done first, to set the stage for non-dual work. But keep it as a possibility.
9) Researching online. This list of tools could go on forever. Maybe some of the things mentioned here clicked with you, but maybe you have to discover your own tools. This is by no means a compelte list here.
10) Allocate time to healing work. Our lives can be too busy and hectic for our own good. Our culture puts way too much emphasis on working, achieving professional success, having a ''normal'' 40-50 h/workweek type of life. And of course it's not just a cultural thing: most of us have no other choice in this current situation. But there are some ways to hack the current reality, to a certain extend. Cutting off stuff that drain you of money and time, like smoking, drinking, pointless socialising (the type you deem pointless by your own standards), buying expensive (or any!) clothes and gadgets, even owning a car when you don't really need one and could be ok with a bicycle, all these things occupy time and resources that could be put into healing work. It's about prioritising your health and adopting a minimalist approach to everything else. And it can go a long way.
11)A good person is not one who has always been perfect. No one is perfect. A good person is one who is actively striving to be better.
also if you've done any of the above healing work (or any other you discover yourself), and you're still feeling stuck in guilt, maybe try pondering what this man says:
David R. Hawkins: "If you feel like you're stuck.." (video on Youtube).
honestly wish you the best my friend
