My Boyfriend is addicted to weed and gaslighting me

I (F20) love my boyfriend (M20). I love him to death. We’ve been dating for about six months. We do everything and anything together. The only thing is I cannot stand his weed addiction. Everytime I tell him he has one, he tells me he doesn’t or he can quit anytime. I’ve heard “I’m young I’ll deal with it when I’m older” very often. His dad is an alcoholic and stoner so he thinks its normal. I grew up in a conservative household and don’t think its normal to be smoking at least 4 times a day. He used to smoke every other hour and also hit his cart, but luckily we had a conversation about the weed intake and he doesn’t own a cart anymore. He’s taken “steps” to get better, but the problem is that he doesn’t want it for himself. If tried positive reinforcement and that just made him think it was ok to smoke more. He has no other hobbies rather than smoking. He depends on weed for eating, driving, working, etc. Subconsciously hes become so bummy and I think a factor is the weed. I’m not opposed to weed by any means. I smoke probably twice a week. I tell him that being high in public gives me anxiety and he said I just have to do it more and get used to it, almost peer pressuring me. He dropped out of school this semester because it was “too much” (was in 6 credit hours only at an online community college) and works 12 hours a week. In his freetime he plays fortnite and smokes all day. It just isn’t the lifestyle I align myself with. I work 35 hours a week, have dance practice at least 5 hours a day, and am a fulltime student at a public ivy league school. I feel somewhat dragged down by his lack of work ethic and wish something would change. Anytime I try to address it, even in the nicest way possible, he completely breaks down, whether it be crying or just yelling. Its exhausting sometimes. Im not sure what to do. I don’t want to break up with him by any means, but I just need advice on how to navigate a situation like this.