I really don't have anything to say that hasn't already been said, but my SO went from constantly getting me off in every way possible for years with me never considering cheating to now turning me down several nights in a row and maybe once a week (if I'm lucky) letting me mount her in MISH while she lays there clearly not into it.
For whatever reasons (likely me gaining weight, tired of doing the same guy, and built up resentment over little things that couples fight over) she has completely lost interest in sex with me and only occasionally gives in but refuses to do more fun positions and bjs like she used to. As far as sexual attraction goes, it is still very strong for her, but I just don't get it near enough and she doesn't try anymore.
I feel like this sexual frustration I have in my relationship builds up and up and up until I'm about to go crazy and then I go see a provider and it relieves the frustration, I feel guilty for a few weeks, then a few weeks after the guilt fades I start getting a pressure build up again. Once a month with a provider can keep me sane, but I would be happier if she suddenly wanted me to fuck her brains out again every night like we used to.