So I already know I'm an asshole, there's no way around it, I let my temper get the best of me and acted fucking stupid. I just want to know what the extent of my assholeness is. So I and my brother are currently in 12th and 11th grade respectively. I bullied him pretty badly in middle school and body shamed him then too, although that was a thing we all did to each other back then we were a very toxic family. But I was definitely his bully not the other way around even though he reciprocated.

Once I(until now) matured out I of my selfish narcissistic ways (and honestly once I got full access to the internet and realized our dynamics weren't normal sibling dynamics) I worked really hard on myself to work on my temper and my toxic behaviors. I became my brothers main defender against our verbally abusive mom to the point where he viewed me as his favorite sibling and acted like I never abused him. I apologized to him about it multiple times and he claims u wasn't that bad and he hardly remembers it. I think deep down he must hold a lot of resentment. So we had a pretty civil and friendly relationship until recently out of the blue he started acting really mean to me. (For context because I know some redditors are gonna say I'm leaving out information and I must've done something, this is a thing he does, I actually suspected of him of having turrets for a brief period because he's just so impulsive about it and it's just out of nowhere and he's done it to a lot of people, but I don't think it's turrets, he can clearly control himself and he only says that kind of stuff in environments where he won't face consequences for it.) He's done this to a lot of people but it's been going on for a really long time already, much longer than normal. We'll be hanging out or just having a conversation and out of nowhere he'll just say the most hurtful stuff ever.

For the record I also have body dysmorphia, but he'll call me fat, ugly, and he'll be extremely specific about it and also say things like "even if you wanted a partner you could never get one", or "no one will ever respect you cuz you look like a perpetual toddler". I've tried a whole bunch of things to make him stop because really, I bullied him in n similar ways and he probably see down resents me for it so I thought it was best to just let him get it out of his system or whatever and really I'd be a major hypocrite for getting upset about it. I tried ignoring him, and even asking him to stop because he was hurting my feelings. But recently it started getting even more mean and happening more often. A few nights ago he started saying stuff like "im gonna kill op" or something. (Not seriously for anyone who accuses him of being a serial killer, more to get under my skin or something) and then last night he just started saying over and over again "you're gonna die alone" "you're gonna die alone" this is directly targeting the fact that I don't want to get married which he disapproves of and was something that caused a lot of conflict between us and us a pretty sensitive topic for me(im an in the closet lesbian but he doesn't know that, we're religious Christian and my "I don't wanna get married" thing is a way to get myself out of tricky conversations).

At that point I snapped and I was like "ok I've been nice to you for a really long time, but if you're gonna be a dick I'm not gonna bother trying anymore" and then I stormed away and went to sleep. Then today I went out early and when I came back he was just sitting there with like a smirk on his face cuz he expected me to just pretend I forgot about it like I usually do, I didn't have a lot of sleep and at that moment I just got so pissed off I let him have it and told him everything I was holding in about how hes disgusting and fat and ugly so he has no right to call me that stuff and how hes actually gonna die alone because hes an inconsiderate ugly asshole who no one could ever like and he looks like a blob. I know that stuff was super terrible to say and I regretted it the moment I said it, and I acknowledge that there were much more graceful ways to handle the situation also I know he had bulimia although he claims he doesn't anymore. After I said that he just walked away but I heard him go to the bathroom and I'm scared he went to throw up.

I can't exactly make up with him because hes been acting so difficult he would probably just ignore it and be really mean back and honestly I'm not in a place where I could apologize and feel genuine because I'm still kind of pissed off. I don't have the emotional or physical strength because I had to pull an all nighter last night so I'm just exhausted and talking to him is too draining and I'm scared I'll end up saying some more messed up shit. Basically I'm trying to figure out how bad I fucked up and maybe what I should do from here. I genuinely regret saying all that mean stuff to him and he was probably just saying that weird stuff cuz of trauma(and to anyone who asks, multiple people have tried to get him into therapy, he refuses). I'm also just so tired of pretending im not pissed off by the stuff he says and I want him to stop because there's only so long I can keep pretending to be unphased.