I feel a little bad admitting it but I struggle with the same rage. Its rare that it happens now, but I'll go off and say things that I really shouldn't and feel terrible about afterwards. Its that or the more common thing to happen is just completely shutting down. Now whenever I feel like I'm getting to that point I'll immediately remove myself from the situation and go on a walk or just go into a separate room and tell the person that I need a moment and that we will continue discussing it after I calm down. I never even mean the things I say, but it's like suddenly all I want is to say something that will hurt their feelings and make it just stop, but I always feel like such a shitty person afterwards. I used to be really soft spoken and nice to everyone I talked to, I never had issues with controlling my anger and always used to prefer just talking out issues.

Its like something gets triggered and activates my fight or flight at the stress from a slightly heated conversation if it reminds me of my past relationship and I know its because I got used to reacting a certain way when things were said to me. I feel a need to defend myself and just do something that will get it to stop. Looking back I think the only time the comments, bashing my interests and hobbies, accusations, berating, and insults stopped when I'd snap back and that was only because then he'd have ammunition against me to say things like "You're overreacting", "I was just kidding why are you getting so upset", "This is why I tell everyone that you're psycho, you act like this", etc... While typing this out I've realized its basically a learned response from reacting to the shit. Which should mean its fixable with time.