please explain the different possibilities with this situation

me and this guy were hooking up during Christmas time. I developed feelings for him, but he didn't wanna pursue anything because I was going back to college which was 4 hours away from home. he told me it was difficult to catch feelings for me since he knew i was going back to school. so whatever I went back to school and within a month he was dating his ex again. I was heartbroken, and he was still talking to me about hanging out when i get home from school, etc. eventually while i was at school me and him had a long talk and i told him that i can't be the other girl when i come home. he basically said whatever happens bw him and whoever is not my business, and whatever happens bw me and whoever is not his business, and what me and him have he wants to continue having. i told him my feelings are involved and he said "oh and you being away at school doesn't affect me?" and i explained how we both want different things, i want a relationship, you don't and that's fine." and he said "its not about me not wanting it! it's about the fact that it cannot happen right now." and then he said "if you wanted something for so long you should have said it." and i said "i'm not going to have any regrets, if i would have said anything, the situation would have remained the same." and he said "i doubt it and you really don't care as much as you say you did/do with that comment." i got over things in time, and I graduated in may and i'm home for good. he has constantly been up my ass wanting to hang out but he STILL has a girlfriend. he drives me crazy and does/says things that makes me believe he likes me, but he STILL has a girlfriend. we had a talk one night about how I don't have a guy and he said "maybe youve already met him and he's just waiting for the right time. law school is no joke." cause I wanna go to law school, and I don't know if he was making a reference to himself. but I feel like its never the right time for me and him. so the other night we hung out and had sex. I felt like sh*t the next day, I don't need a lecture, I feel like a horrible person. after that I told him we couldn't do this anymore, he ignored me. then I said "are you gonna say something?" and he said "what do you want me to say..you said it can't continue so fine it can't continue." so then I had a weak moment and said "nvm we should hookup" and he just started ignoring me. I was texting and calling excessively, it was psychotic and out of control, I will admit that. but now he blocked my number and blocked me on Facebook. I'm so upset because I was out of control and I apologized for that but he makes me this way. also, we fight all the time. and he told me he was getting fed up with it, and a person that fights with him all the time is not someone he wants to be with, and I don't give him a reason right now to "reconsider his situation." MEANWHILE the reason we fight all the time is because he has a GIRLFRIEND. i'm so hurt because now we don't talk at all, it's been 2 weeks and i feel like it's my fault because i was acting so crazy, but at the same time, i acted so crazy because i'm so confused, hurt, etc. and it's always an emotional rollercoaster with him. he plays with my head, and it's heartbreaking.

1. what do you think about this situation?
2. do you think he could have feelings for me? or was it just sex?
3. whats the real reason hes not talking to me?