It might be worth a conversation with your gp, sometimes a very low dose testosterone supplement can help in older women. Talking it through with your OH and having a spell where sex is off the table for a fixed time say just two weeks, then start with a non sexual touching phase, massage etc, then external sexual touch , trying to relearn old responses and maybe discover new ones. It's easy to get stale and to the point where you can't be arsed. Being honest has to be the way forward, has your OH let himself go a bit, if you discover its that you don't fancy him, rather than just not fancying sex with anyone he has a choice as well as you. I wouldn't grin and bear it you could put yourself off even more.
Just make sure you don't lose the emotional intimacy, talking, touching , that closeness might just get you through.