What should I do?

My boyfriend and I have been together for almost 3 years, and he’s the only guy I’ve been with. We met in high school and I’ve just started college. I don’t really know what to do, I love him but I don’t know, it’s different now. It seems like every time we hangout he just wants sex. And that’s kind of how it’s always been, but I’m tired of him always pushing and begging. Then getting mad when I say no, it’s just really tiring. I know it’s wrong but I’ve been thinking of other guys, just getting to know them. I don’t know what to do! I don’t know if I want to be with him or not, I need advise.