How to deal with my partners meltdowns?

Hello, I am writing this post because I’ve exhausted my options and don’t know what to do.

So me, (25F) and my boyfriend (25M) we’ve been dating for almost 3 years. I have known since the beginning that he was autistic and had ADHD. And he also knew at the beginning that I had BPD and depression with anxiety. 

Our relationship at the very beginning was very chaotic, we would breakup and make up constantly, due to my triggers from bdp I was always very upset whenever we would fight and very easily i would breakup with him as a way to protect myself, but he would always come back begging me and calling me to get back together. Mind you, 3 months after dating him I discovered he was messaging his ex asking some very explicit things and when I confronted him he told he didn't even know why he talked to her that it was just an old habit and that he would stop, well after dating for 8 months he did it again and I broke up again and in between I hooked up with someone else just out of spite because I didn't wanted to end up back together but we did. After the 1 year together mark, things settled down let’s say, we each forgave one another for the past issues, and we were trying to go forward, we didn’t live together but we would spend a lot of time together, me going at his place, him at mine. It’s not after the 2 year mark that things started to become hard for me. As the beginning  chaos settled  down well, we were somewhat having a normal relationship, it isn’t until well we would argue over something, sometimes very small, and it always end up with me crying and feeling misunderstood and him being on his phone not answering me and shutting down completely, we almost broke up again because everytime we would fight it would always end badly, like we never came to an agreement in the end of an argument. And as I said before I have BPD so my way of coping is not that great and I would often time s*elf h*rm because that was my way of externalizing pain. But I was under medication. I would see a therapist every month and he on the other hand, besides his diagnosis as a child he never went to see a therapist. 

We only recently ( 8 months ago) started living together. 

The reason I write this today after almost 3 years together is because something happened that quite frankly scared me.

So 2 days ago, we were each doing our thing, him playing games and me cooking when out of a sudden he told me he wanted me to stop talking to him, I did not because when he tells me these things it sounds very rude and like a command, and I already asked him to not use such tone and words as it triggers me. So i reply to him saying “ no i will not shut up” and like continue, usually he eventually stops asking me to shut up and i stop then talking. But this time he completely snapped, he screamed very loudly to tell me to shut up and punched his desk so hard as to almost break his whole setup. I froze because he never did that before. I understand that I must have pushed him by not giving him his time alone but I never thought it would lead to that. As I have some ptsd and triggers from my childhood (my parents would beat me up as a kid) obviously being yelled at doesn't really sit well with me. And yes I have told him in the past about my parents and how badly i react to being yelled at, he knows it. So I stopped cooking, took a bag and left our apartment. I was in shock and I started crying. Before leaving he asked where I was going and I told him it was not a normal behaviour to punch things out of anger and he told me it is because I upset him so much. So as I was outside crying and walking around our neighbourhood he did not try to call me or go after me. I spent maybe 3 or 4 hours outside and came back to see him playing his game on the computer. I Settled down and asked him if he was ready to talk to which he replied” no” very coldly, after a few hours i eventually forced him to talk, because for me his outburst scared me so much, i frankly was afraid that if i ever make him mad like that he would be hitting me next, but that is my trauma speaking i think. So I tried talking to him and he would be very dry, and almost numb as if he didnt care about what I was saying. He would only answer me with grunts or yes or no, but he would not make a full sentence. I know that he was also upset about what happened but the problem I have is that he thinks it’s my fault. The only thing he said is :” it’s not me it’s you, you are the one that pushed me, i didn't do anything”. And so i was talking to him and telling him that if we don’t resolve this i might have to leave him because well i was scared for my well being and uncomfortable around him now. 

When i was talking to him it felt like i was forcing him to talk to me as if he was being told off as a child, but i don’t understand how he could not see the harm and gravity of what he does. I love him alot and besides those moments when he is in a good mood we have loads of fun together. I want to see a future with him but I feel like he doesn't even try.

I told him plenty of times in the past that seeing a therapist could be useful, just the other day I brought it up again to which he just said “no”. It’s been 2 days since his outburst and he hasn't talked to me, he slept on the couch for the last two nights without me telling him, he also barely eats. I feel bad for how he is reacting and wish i could help him but in the past nothing i did worked, and i’m coming to a point where I'm becoming extremely anxious and afraid of his reactions. I really don’t know what to do. When I'm being soft and kind he still is upset, when i try to hold my stand and be firm he still is upset. I don’t know what else I can do besides breaking up with him, but I love him so i don’t want to give up on us.