Sometimes you just have to let go of things that are bad for your mind, body and soul. Sometimes anger comes out of a dark hole, to blanket and cradle hurt. Sometimes the emotion anger is not the feeling you wanted to enter the situation, but the mind, body and soul goes into defense mode. Sometimes that just happens. When the anger crawls back into that dark hole from where it came from, you're still left with an uncovered and naked hurt. That needs to be dealt with. I think, me personally, I have this part of me that wants to fix things. Analyze to the point of exhaustion. Letting go is hard. But letting go is realizing it can't be fixed. Sometimes some people are not good for you.
The mind, body and soul is a machine, that well- oiled is capable of amazing things. Healthy thoughts, running up hill and loving. When it's being fed poison, it will react just as that. It can't function properly! As humans we are capable of enduring emotional abuse, physical pain and heartache. With time, all those things can be healed. Sometimes letting go is hard, but it's the only way your machine can get back to functioning, with that well premium oil we all look for in life.
This too shall pass. Forgive yourself and others. We are only imperfect machines, sometimes. But resilient humans, always.