Autistic boyfriend help

I am at my wits end with my boyfriend. He has no official diagnosis other than dispraxia and dyslexia but am sure he is autistic. We have been an item for two and a half years. We are both in our early 20’s. He is for the most part loving and lavishes attention on me but has no idea of when he has upset me. He feels we argue all the time and we don’t , or if we do it’s little spats I feel. However if I retaliate if he says something nasty to me and I apologise he will bring it up weeks later. 
he has to go away to work and when the opportunity first came I told him to go for it and he told me he was glad I had been so supportive as it made the decision easier for him. 
however it’s coming close to him going and nothing I can do is right. He  over me suggesting a type of car as he has to get a small runaround at the new place. He went so mad he threw me out of the house and locked the door. When he slammed the door he caught my foot and I swore at him but apologised immediately. He appeared to accept it and we talked through out the day . I asked him to come to my parents for food and he flipped again .. he has to keep a vertical weight for his job . I said forget I said anything . He then thought I was being sarcastic and flipped again telling me he was so stressed and I was making him more stressed and that he hates me and wishes he never met me. This was all over the phone I was crying, he did not react only to say he didn’t want to speak to me. I love him very much and have only ever supported him. I apologise if I am in the wrong. He told me he was a little nervous about the job but nothing more. He only seems to take advice from his dad. Help please