What's a good way to get my boyfriend to stop smoking weed?

Cannabis: Tell him specifically (in a non-aggressive manner) what your concerns are. You can encourage him to consider ma (marijuanna anonymous). But you can't make him go. You can care for yourself by attending a 12 step program like al anon. If he is not willing to stop his cannabis abuse and you find it intolerable - ending the relationship is certainly an option.

We can't control: Other people's behavior, no matter how self-destructive it is. Let him know that it bothers you and your specific concerns. If he isn't aware of marijuna anonymous meetings let him know about them. Don't enable his drug abuse. Remember that ending the relationship is an option. It sounds like his drug abuse is upsetting to you - consider going to al anon meetings for your own sanity. Take care.