That is a tough situation. Have you taken any medications that decrease your sex drive? Antidepressants are known for this as well as other medications. Another possibility is hormones. I think low estrogen causes dimension sex drive. Low estrogen symptoms are reduced sex drive and painful intercourse.

I think for anyone who is married, sex drive comes and goes sometimes. Stress and life events can put an emotional load on someone and reduce their desire for sex.

You pain during intercourse is troubling. You may want to talk to your doctor to make sure everything is ok.

Is it just sex, or is it intimacy he is after? Could giving him oral sex meet his desires? Being on the husband side of this it is frustrating. I don't know what your husband is like, but sometime it is just an urge you can't shake away with reasoning. It seams like sex and reason don't go hand and hand for us.