Idk. I mean like Pinkviolet and Angelique touch on, there is the oral sex conflict. You mentioned that.

It also sounds like a rut and boredom. I feel like maybe you're exhausted with her inflexibility or inability to climax, no fault of her own. Maybe you two need to accept the idea of exploring toys, or some other aides to help her get her off w/ you, or more FOREPLAY. It's just an idea for solving that, Idk.
As for your interest.Wellllll as much as it does upset you to think of it, what does kinda interest you? Maybe she can dye her hair, try on outfits for bed, to change it up. I mean obviously you still adore her, otherwise you'd leave her or cheat, so I would be REALLY tactful about introducing these ideas if they appeal to you.
If not, theres always the old renting a porno, and banging. :/

*subliminal messaging: FOREPLAY *
(^Not necessarily directed to the OP, but to any man who catches this!)