Sexual want mis-match

I never want to have sex with my husband. I used to believe it was my duty and so I did it; but I no longer believe that, so we don’t have sex anymore. He wants it, and has stated that. When we were married we both held religious beliefs that sex was very important in a marriage, which, again, are beliefs I no longer hold. So I feel bad, like he’s now trapped in this sexless marriage he wasn’t expecting unless he wants to divorce (and he doesn’t want to divorce, nor do I).

It seems reasonable to want sex with ones spouse, but our relationship started out platonic and never moved past that for me. We’ve been married 15 years. I wish things were different, which is of course unhelpful. I have long thought I’d be fine never having sex again for the rest of my life.

I would love any insight here.