This is probably a circumstance where taking sex off the table completely would be helpful. I had the exact same thing happen with my wife. I gave up on sex, stopped seeing her as a sexual being, and when she eventually wanted to have sex it was incredibly awkward and upsetting.

We talked about it and came to the conclusion that we should be a platonic couple, and it's honestly been wonderful since. There are no awkward moments any longer. We can watch a movie and go to bed, and there isn't that weird tension of "we're not sleepy, but we're in bed, and you know what people do in bed." It's just 100% known what's an option (reading a book, getting up and watching TV, going for a walk) and what's not an option (cuddling, having sex).

It's honestly freeing and out marriage is as good as it's ever been.