What do I do? Any help? (Read below)

So a guy I've been seeing recently cut me off after like 8 months of talking and knowing each other. I really miss him and I want him back but he blocked me on everything and hasn't read any of my messages and refuses to reply. What happened?

So I accused him of talking to other girls (I did this more than once) and he got angry and really mad and he said he'd had enough of me constantly creating arguments and not trusting him... Fair enough I knew I was wrong but I had my reasons. So right after I tried to apologise but it was too late because he already blocked me! Like that quick! He didn't even let me explain, he didn't even give me an explanation why, he just left without saying a word and it hurts like crazy and I miss him so badly and I would do anything to get him back but he's so mad. I just want closure , even if he said 'goodbye' I wouldn't be hurting so much bt he said nothing. He kinda just left... Obviously he said he couldn't be bothered with me right now but I didn't think he meant he would leave. What do I do? It's been just over a week and I'm scared he won't come back. How can he just pretend I no longer exist to him? :( Really heart-broken!