I can relate, almost entirely to your early childhood
I have a colourful past and one that falls in line with your early years. (including the baseball bat and knife fights actually, its kind of eerie)
I was lucky and got some counselling to deal with a lot of my misplaced anger, frustration and angst.
As for the "its my fault" syndrome, if you figure out how to solve that let me know. I know...I have to trust in the person I am having a challenge with, but that sometimes doesn't work. I think it is sometimes human nature to search for the cause, and sometimes you have to look in yourself. When my ex and I broke up I spent a long time looking at everything I did, nitpicking to the minute, or things I didn't do that might have fixed it.
At some point you have to stop looking to the past, realize the reality and stop mourning the loss. Celebrate what you had and move forward with those lessons. It sucks ass until you realize that, hurts and is painful. You are in fact mourning the end of something. You are a fighter, unfortunately this is something your can't just beat up, so I imagine some of your pain comes from that. Fight or flight doesn't work here...it just is.
Soooooo onto the bigger topic, no coping mechanisms. Congrats on recognizing it... now to the meat - Have you sought counselling SPECIFIC to that. Understanding your emotional burial and now its revival, you have been hung out to dry. People don't give enough credit to people who have never been taught how to deal, and some of us need that. I did...in many ways it backfired too, but I was able to deal. During times of duress and anger, those emotions ALWAYS show up as sadness. Being sad is better than feeling the rage again. Is it healthy, no, but it is something I am dealing with.
Seek help, find someone who specifically deals with sociopathy and understands with your newfound emotions you are really at the emotional maturity of a 13 year old. Having to learn everything that should have been dealth with through highschool.
Some things I can recommend which might help. And this is for your partners too
1 - if you are feeling a huge emotional swing - stop, walk away and ask for time. Don't. EVER make decisions or arguments during the swings. Your challenge will look like bi-polar depression when in fact its just your body not knowing how to deal. Take the time to control that swing and then re-engage. Fight that urge to fight
- now, here comes the downfall. Ensure you watch for the upswings too. The extreme happiness is not good either. If you let yourself ride too high, the downswing can be really intense which makes it worse. Try to fight the large swings back and forth.
2 - You need to, during times of normalcy, ensure you inform your partners of the number 1 requirement. If you just walk away they need to know why, come up with a code word if you have to. But find that time to settle yourself and ensure they know why. Spouses/partners can react badly when you run away, and chase. NOT GOOD in this situation.
3 - Never put yourself in a situation where your learned instincts can kick in. Feeling anger, rage or sadness. Don't put yourself in a situation where a fight can happen. Your instinct is to fight, you have relative control of it....during intense times I bet you don't have as much control
4 - go to couselling
Have I mentioned counselling yet? Learning coping skills on your own is totally possible, but it sure is easier with help.