DEEPLY In love with my ex-sex friend.

Hey guys, I'm in deep deep shit.. I seriously am , I'm no longer able to study or do anything, and I'm on my finals damn it ! So , there's this guy , we were really good friends , once we drunk with some other friends and he started to kinda seduce me by playing romantic things but he didn't actually do anything , that's when I first wanted to have him , after a while he asked me to be his sex friend so I totally agreed (ps: I was still in love with my ex at that time) It was awesome , we were super good friends , we hang out we see each other every single day (we study @ the same school) , we always talk on facebook and skype etc.. and were doing the sex stuff. at that time I really loved him but as a friend , I always told him about my ex and all , and once I started crying while he was kissing me cause I remembered my ex --' (pretty stupid I know) anyway life was peaceful , everything was awesome . I was happy. until , once , he was kinda busy he didn't talk to me all day , and he was kinda ignoring me , I got mad. that particular day , his friend called me and said he's gonna come see me , I said yes. we were in his car and he kissed me , I didn't push him back . I got home and told my sex friend about it . I must admit it I told him about it on purpose , it was kinda "revenge" or something or just me being stupid --' anyway , he was like ooh ? okay. awesome. I apologized and all.. and BAM! since then , he became another person , he no longer called me or asked me to hang out after school nor did he talk to me on facebook the way he used to do . He even started avoiding the sex thing, like "I don't feel like it today" It took a month so I burst out and told him wtf is going on ? he denied that something was going on and then he finaly spoke , he said that the kiss I had with his friend set him up and that he no longer wants to do this. We stopped the whole thing , that's when I realized I kinda had some feelings for him , then we got back , and it was ALL SEXUAL. He asked me for nudes ,he no longer acted the way he did , when I asked him what's wrong now ? he denied it . He told me that we're just sex friends that's what sex friends are. And he sometimes admitted that the kiss changed the whole thing. we kept on doing that and by each Time i get worse.. I couldn't accept the idea that he wanted me just for sex , I officially fell for him. until yesterday , I couldnt take it I went straight to him and told him that I had some feelings for him and I wanna stop this, he said that he knew it. END. we became total strangers :) what should I do ? I can't see him every single day without talking to him Im dying inside , I really need some help. thank you.
PS:he used to act jealous every time Im around a guy , he didn't talk to his friend (the one who kissed me ) anymore , he used to ask me where I was and with whom and was I alone with him or not , => he used to show me that he cares.
PS2: he's the kinda mysterious guy , he never talks about how he really feels.