Healthy relationship advice?

My Boyfriend and I have been together almost 3 months, now we are sexually Active. I feel like sometimes he only comes to me for sex or money, and I know that he’s cheated before. I really really love him due to knowing him before getting into a relationship and he’s been really really sweet and caring when he’s around. But lately he’s been very cut off and he doesn’t want to talk to me and it’s been about a week since we’ve done anything other than like maybe a text? But that’s about it. I mean I want it to work it out and I want to be with him but I also don’t want to feel like a second option or that I am stuck in a relationship.Please be nice, I’m only about 20 and I’m coming for advice on how to talk to him about communicating better. Or if I should just move on and decide to leave him…