Breathing techniques, Can they do damage

[Mulky]

I used to love breathing meditation, and engaged in it with a lot of reckless intensity.   IT seemed to yield great benefits, especially in the moment experiencing euphoria and also working through blockages, finding depths and heights of beauty and intensity.  At one time I referred to it as "getting high on your own supply".  At times I would notice that in a way my behavior was not that much different than an addicts, and I would experience anger and resentment at anyone or experience blocking my ability to experience this.  Eventually my breath openened up enough to stay open, and my breath stayed big and full for years.  You notice many strange things, and find strange experiences like explaining to your boss that you actually can't wear your pants tight, and that is why your clothing looks sloppy.  Your breath is that important. 

It yielded great benefits, including eradicating fears and behaviors that had I gone through conventional means never would changed, it's like I became a new person.  

Now during intense deep breathing(the way i always did it, the closest thing would be the wim hof method, but without holding your breath, just continuing the deep breathing as often as possible, while watching the flow of feeling energy moving up and moving it through everything it seems to be blocked by, even all day if you can.)  there were times my whole being resisted it, and some kind of inner "knowing" said that it was just part of my psyche trying to prevent the ego death etc, or fear of going through the really deep emotions.   While that may be true, I can help but think also my body was worried about like some kind of nerve damage.

It turns out, I do now have a lot of unatural feelings in my body, mostly in my face and heart, that feel odd enough that I wouldn't be suprised if they were some type of nerve damage.  I have not done serious breathing work in over a  year, and I find this yearning and desire to get back into it again.   It is true that the breathing itself makes the symptoms feel much better, but am I like burning my nerves out here or something, am I getting pleasure now at the expense of nerve damage later?  

I haven't gotten into it again yet, but when I have gone into my breath somewhat lately, it isn't like it was years ago, it isn't crazy intense bilssful light colored movement, its just kinda full clear breath but sort of normal and no beautiful intense energy there.  Theres not really anythign visual to go with it, not lights etc.  Is this justr because I haven't gone deeply into it enough again? There is like this reluctance to go deep into that again, and I;m trying to figure out if this is a wise or unwise reluctance.  for me its not as though I sit and do breathing excercises for 10 minutes, I end up doing it all the time as I do other things, ideally walking.  Anyone who knows a lot about this have any thoughts or insights?  Should I go back into breath full force, am I now past that, did I do damage, etc.

Another caveat, it is possible a lot of the uncomfortable sensations are just known more during this time of deep breath, ability to feel deeply.  Because at times i would feel pain in my heart when it was appopritate, while others claimed they could not feel that, as though they were numb.  So maybe that pain was not caused by breathing meditation but I was just more conscious of pain that made sense and was healthy? Like I can easily go shallow with myself and not feel wierd, but then I also cannot feel deep bliss etc.  thanks gang