TIFU by cussing out a no coworker

Hi all I(25m) just wanted to start off by stating I have bipolar disorder and PTSD, I know, not a pretty combo, but I am actively getting medical treatment and counseling. I work in a “casual dining” restaurant, one of those where you can watch the people cooking. I have a coworker (20m) Michael, who gets bored and likes to say some pretty over the top things to people to get a reaction out of them. He genuinely thinks it is really funny to hurt peoples feelings. No matter the reaction he gets he will claim it’s just jokes and keep egging it on, almost as if he craves confrontation. Today he was harassing one of our coworkers to the point where she was screaming so loud the customers were visibly uncomfortable. I advised my manager to separate them but he just kind of shrugged it off, which is typical for him to do whenever anything happens that he doesn’t want to deal with. After a while Michael gets bored of bugging our other coworker and drops it and we all go about our day. The night starts to wind down and I head to the back of house to do a few cleanups before I leave to lift some of the weight off the closing crew. As I am filling up some ketchup bottles Michael sneaks up behind me and screams as loud as he can in my ear. Before I go on, I want to clarify, I don’t go about my workplace trauma dumping by any means, but this guy yells a lot, which makes me tense up due to my PTSD, and I’ve let him know I would prefer if he wouldn’t do that around me. He’s done it about 4 times in the last week and I’ve calmly reminded him, “hey I didn’t have the best childhood, I’m not going to get into it but I really need you to not yell so close to me” to which he goes “it’s funny tho” and I stand my ground and repeat what I had said, and he’ll leave me alone. Knowing all of this, when Michael screamed in my ear tonight I was sent back to a very dark and scary place mentally and a switch flipped in my brain, I blinked and completely lost my shit. I mean chest pounding body shaking, trying to keep my calm, but failing. I whipped my head back at him and just let loose. Screaming “how many fucking times do I have to ask you not to scream in my presence” he goes “nah this time it was just to scare you” I threw the ketchup across the table and let all of my rage consume me, half of it I blacked out, but I remember screaming that he is a “worthless piece of shit who does nothing but ruin the lives of those around him” that he “needed to be put down like a rabid dog” and all he could think to say was “hey, language.” I then clocked out and told my manager to “go get his bitch on a leash” and that I was filing a formal complaint with HR about the toxicity in the workplace and if Michael isn’t fired for the constant harassment of his coworkers I will be transferring to another store, which isn’t a hit our restaurant can take right now. I’m not going to say I’m the backbone of our store by any means, but I am one of the stronger players, and a loss that they would struggle to find coverage for. When I left and the rage subsided I had one of the worst panic attacks I’ve had in years, I couldn’t breathe, I couldn’t think, I couldn’t do anything. I laid on the side of the road until it passed and made my way to a gas station to get some water. I then called and emailed our HR hotline and let our general manager (my managers boss) know about the situation. I know it was wrong to scream in response, especially because I have known for so long that that’s what Michale needs me to do. But in that moment I could not get out of it and ultimately left the building not only for my own mental state, but I could feel my aggression building up to physical violence and that is not the type of person I want to be. Now that I’m home and have been able to collect my thoughts I’m really upset with myself for the way I responded, and genuinely worried I may lose my job over this. Thank you for taking the time to read, really just needed to get this off my chest.

TL;DR coworker screamed in my ear, I called him a rabid dog that needed to be put down.