Boyfriend cant come on to me?

I've been with my current boyfriend for 2 years and our sex life has always been fairly rocky but it was getting much better and has been for months.

All of a sudden, I realized we hadn't had sex in over a week so I mentioned it to him. He said we would that night... That ended up not happening.... And the other night, he told me he just didn't know how to come on to me. Which makes no sense because that's never been an issue for him.

It's now been two weeks and we've only had sex once.

I dont know what to do about this, any advice or anything would be super appreciated because that comment has been really bothering me ever since he said it.