What should I do?

I'm 18, starting college in a few weeks and have been dating my boyfriend for 7months now. He is by far the best boyfriend I've ever had and we are pretty serious, but part of me feels like he's just not the right one. He doesn't value school or think it's necessary at all, and I'm going to start my medical education which requires a lot of dedication. I'm scared he can't understand the demand it takes to go into a health career. That along with some other differences that I feel like clash are making me iffy about our relationship. Part of me wants to stay together but the other part wants to break up before we get more attached since I don't think it is going anywhere in the future. I don't want him to think it's his fault, because I just think it's the wrong time. What should I do?