Hey man, I’m not saying this is the case, but when the sex stopped with my ex-wife it’s cause she was getting it somewhere else for a year and a half. Mind you she was awful and we had only been together 7 years. But also I’m 14 years younger than you.

On the other hand I would not say just leave her. If you’re religious maybe talk to a pastor or priest. I had a priest say to my ex that if she’s not in the mood she may have to just take one for the team because that’s what a relationship is. Sex is necessary for the intimacy especially for the men. Talk to her, have other people talk to her. If she still doesn’t relent for your sanity then maybe she just doesn’t care anymore and it is time to leave. If she begins to relent, then it may take time for her to be comfortable with it. Just my thoughts. Best of luck sir.