Hi there. I feel ya. I have experienced similar drained feelings. With me those feelings come from feeling powerless. Makes perfect sense, feeling no power = feeling weak or drained. And there is only one way to fix that, empower yourself. Don’t take any shit, assert yourself more, work on communication skills and setting healthy boundaries.
Hope this feels like the correct answer for you. My parents also lacked the skills required to be assertive and I have watched my mum loose many friends because resentment builds up and explodes making her looks like the bad guy when really she is too kind. This is something i am dedicated to building as it’s essential skill.
good luck