Just not interested in sex...

So I am 25 years old and just don’t enjoy sex. It kind of hurts, and I think that makes me not interested. But I’m also just never ever horny. I’ve had sex many times with many guys, including my boyfriend of 3 years. We currently live with roommates so it’s not a huge issue now, we don’t do it because they are around. And I give him head occasionally and whenever we vacation ( once or twice a month) we always have sex. But i’m never actually horny. I could live without it no problem. My doctor says it’s normal but I want to want it. Any tips?

Part is me is worried that if he’s not getting it from me he will start looking elsewhere.

Sorry if this is all over the place.