I won't suggest that you read The Passionate Marriage because it seems you've read this.
Something about your H jumps out at me. Where does he get his expectations about how a passionate M or sex looks like? Is he unhappy because his expectations are not met or is he unhappy because he thinks that he is not fulfilling you and he thinks you're unhappy?
He seems to be pretty hung up on physical symptoms as barometers of sexual and thus M satisfaction. Could it be that this issue is a smokescreen for other issues?
Before I ramble on and forget what I want to say, the point I want to make is that instead of viewing sex as a 1 course meal, why don't both of you view it as at least a 3 course meal?
And you dont always have to have all 3 courses. Sometimes, appetiser, sometimes dessert and sometimes main course. Not all meals have to be mindblowing Michelin starred meals. Some meals can be meh.
Also have you considered sensual but not necessarily sexual contexts and activities? Massages, and eh, performances for his eyes only etc etc?
Disclaimer though - this is advice from someone who didn't manage to save my M.
I apologise if someone else has made the same suggestions because I skimmed through your thread rather quickly.
You can call me Dory/ Grl.
As a wise fish once sang,"Just keep swimming!"
It's no use to go back to yesterday because I was a different person then.