I need some help with a Marijuana addiction???

My BF whom I have a baby with is smoking, and I don't like it. I feel like he's wasting his time and I've told him but no matter what, I end up being the one who is wrong...he says that I am always trying to change him, but I do not believe I am, I'm just trying to help him better himself but he cannot see that. He thinks that marijuana is just something he does, like how I study and go to school....I'm tired of his habit and I'm stuck because I love him but I hate what he does.....what should I do, I'm still young and I know I can find someone else, but I don't know if it's worth going through another relationship...what if it ends up the same or even worst???

: http://alcoholdrugstreatment.info/i-need-some-help-with-a-marijuana-addiction