*Long post, please help* My now ex boyfriend is doing drugs, texting me crazy texts and CANNOT get over me. I still care for him, what do I do?

Rylee
My now ex boyfriend and i had been dating for 2 and a half years. When I met him he was going to parties like crazy, moving on to some drugs like pain killers, uppers, or things he doesn't even know what they were. I calmed him down, and made him do his school work. It turns out this kid is a genius but he would never believe me because he was in a "special kids class" (only because he was dislexic and our school system is stupid). He had no direction in his life until I met him. Well for the last good part of our relationship all we did was fight. He is one of the few people who can make me as mad as I got. We tried working it out and we even talked about breaking up but never really did until one day I was dragging my butt to go see him, like every other time, because I knew we were just going to fight again. I realized I was tired of being angry. So I broke up with him really easy. I knew he wasn't going to be his best but now he is just crazy and wants to get back with me (and I know that will cause more problems). He will tell me things like "I can't do this anymore" and he'll want to see me and I'll tell him that it's not good for us right now, maybe in the future "I'm not going to have to worry about the future." The last time I saw him (so he could give me back some of my stuff) He told me he saw one of his old friends and smoked some sort of pain killers. I went off on him and asked him if he wanted to end up like some of our very close friends and he profusely apologized. I told him he has a future and he can have a great job and whatnot if he doesn't screw it up. I told him not to screw up his future and I would accept his apology when I saw change. Then he told me how he missed me again and I held him (because I still care for him and it hurt my heart to see him like this). He hasn't slept and barely has eaten anything. I don't know what to do. He WILL NOT go to therapy or anything like that. What do i do? Please help :(