Weeeeeeeeeddddddddd addiction?

My boyfriend's addicted to weed, normally I wouldn't try an act like such a controlling girlfriend, i don't believe in relationships where someone is taking something away from you i believe that if you are unhappy with that person and what they are doing then you should leave but sometimes it's not always that easy and i don't like to do this without trying to help that person. So, i am trying to help. I have already broken up once with him but we decided to get back together. He truly is a great guy aside from his weed addiction and i don't think it is worth losing every other good quality he has just because he smokes weed too much i left him once for that but couldn't get over him and if weed wasn't in the picture things really could be a lot better. I just want to help him but nothing i do is working. I've gotten mad, i've yelled, iv'e ignored it, iv'e tolerated it for a long long time, i've calmly tried to help him discover why it is he is so dependent on it and how he transformed so dramatically since i met him on the subject of weed. I know telling someone to quit just won't work until they really wanna do it for themselves but there's got to be another way. I've been mean and i've been nice and no conversation does anything. He went from never smoking anything to trying it here and there to doing it at parties and my best friends smoke weed then i started noticing all of his friends smoking weed so now everyone he knows smokes and it is too difficult to get him out of this environment im not saying don't be with your friends just do something else for a change. Now he spends hundreds of dollars on weed and accessories vaporizers, grinders, bongs, bowls, trinkets that like roll a J for you in two seconds...he works goes to school then blazes with his friends and listens to music or plays videogames about everyday...im at school out of state but am transferring back home next year and im not around to be with him but still EVERYtime i call him hes in the car or at his friends house "chillin" which means smoking and its L-I-T-E-R-A-L-LY every single day...he never wants to talk about much of anything else and never really has much to share except anything related to weed which gets extremely boring. He spends most of his time researching new equipment for it or looking at cartoons about it or watching movies about it. He has a very obsessive personality and once he likes something he likes everything about it and its never-ending. I never told him he had to quit and never cared that he quit entirely i smoke weed occassionally too but i can also pass up an opportuinity anytime i want and do often and smoke like here and there i don't live by it...he does and its just not good.what can i do......meanwhile he still gets straight A's so im proud of that and he has a job and is on time blah like its not interfering with anything except his social life but its all he does and i can't see him quitting ever...what can i do...have you been in this situation? I am starting to believe we are not going to last because of this but this is our second try and were supposed to go to school together next year and its supposed to be awesome but i really don't see it being a happy experience because of this and btw im not going to school just for him so i don't need comments about switching schools for a relationship...if that were the case i wouldn't have left for a year in the first place...but anyways...please help. thank you