2 years and no talk of the future

I've been with my boyfriend for over two years, I do love him. And could see a future with him. We've been together since we were 17, now we're 19 and 20. I get we're young, but I only do serious relationships. I think about the future and can see him in it, even if it's just as friends. Like with my exes I don't care about them, but I know if me and (gonna call him C) broke up we'd still be great friends. He is my best friend hands down. I could never loose that, but whenever I bring up ANYTHING in the future he brushes it off and changes the subject. I wouldn't go as far as saying I WANT to spend the rest of my life with C; it could be a possibility, however I really don't see that happening. People say only stay in a relationship if you can see a future with the person or want that future with them. I love C, but I don't see us staying forever together. I know if we ended it we'd stay friends at least, to be honest I think we'd work better as friends. I don't know how to voice that to him. Because I don't want to break his heart, but we're young. He's my BEST friend, I don't wan to hurt him. Also I lowkey need a ride back to uni. I think if he was more serious about the future I'd be happier in this relationship. Do I bring that up to him? In two years we've never had a serious fight, I don't want to loose him as a friend. My last relationship was from May 2016- June 2017. It was a crazy toxic relationship. I wanted to break up with him around Christmas because I didn't feel loved, kept pushing it off. Christmas day he literally made a like photo book of him and me. It was crazy sweet, so I thought okay. I'll stay with him. I can't break up with him now. So I suffered till June, then he broke up with me. I'm terrified of confrontation. I've never broken up with someone, for a reason. Do I bring this up to C (my concerns) or do I wait till I get back to uni and break up with him? Just seems a shame to throw a two year relationship away like that.