I am a low desire hubby, 2 things, have affected me. 1) She gain a lot of weight, and somewhere in her 40's her sex drive went way up. And sex became work, we did not know how to fix it. So it just got worse.
We went from once a week, to every 2-3 weeks, I just plain did not know how to fix it, nor did I have the relationship skills I have since learned. I was not nuturing or did I know her LL. I believe had I knowed how to fill her love tank sex would not have been an Issue.
I did do a idiot thing, on occasion I use denial of sex to get back at her for something stupid.
I don't think you can fix it without help, I think MC is called for.