I was in a bad relationship and now I need some advice!!!?

This is a long one- but i need all the help i can get.. so I basically have an extremely complicated boyfriend problem. I've been in an on and off relationship with a guy for about 3 years. He's 21 and I'm 19. And though I know we both love each other our relationship is definately not a normal healthy one. A lot of things complicate the situation. First of all, We've grown up living in the same town and this past fall I moved over 1000 miles away with my mom to go to a junior college near her until the end of the spring. Second of all, he's got some of his own issues. He's been heavy into drugs not long ago (painkillers), and although he's finall realized he's an addict and goes to the doctor now and is on meds- he's not really on a straight program or seem totally motivated to get better, and he's also still best friend with some of the guys he did the drugs with. Third- I just feel a total lack of respect from him anymore. As far as cheating goes I've asked people he works/hangs with if he has and theyve said they dont think he'd do that to me- but i'm still not sure since he's lied to about about lots in the past. Our relationship has never been the normal kind I've wanted- and for that matter what almost all people that are in one want. I just want simple things- us to be able to hang out with friends together- him to be able to be around my family- us to go out more together when I am home or at least to spend more time together- and for him just to not be so secretive. I used to have all of the self confidence in the world- and now I feel completely insecure. I'm a gorgious, intelligant, and fun girl- I know I'm worth a hundred times more than this relationship- but the fact that heeee doesn't seem to agree hurts me like hell because I've gotten almost addicted to him. It's even changed my personality for the worst- I've become psycho crazy half of the time and pick fights with him because he wont change and cry- and I mean no wonder hald of the time he doesnt want to talk to me or deal with it. But ive just become so tired and frustrated. After a freak out I had last week I basically just bluntly just told him to leave me the hell alone- and he has. I've broken up with him sooo many times and have run back- I'm sure he thinks this is no different- although we haven't talked in almost a week now (he's IMed me a couple times but i never answer). I guess I just want him to realize how bad he messed things up with us and whatnot but I feel like in his mind I'm always just going to be just another girl- even though I basically sacrificed my own life to try to help him. And what scares me even more is that after leaving him the next girl he meets is all of the sudden going to change him like I never could and I'm ultimately the one that gets screwed over. Should I just leave it as is and not talk to him for a while? I'm actually going home in a week if that helps at all...would it be better if i just completely didnt see him when i go home??