Pretty astute and well-written post, if you don't mind me saying. I especially liked the way you expressed this feeling of possessiveness over your woman:
I don't even like sharing something as trivial as a checkout line with another man, so sharing something as important as a woman's love and intimacy and affection? Impossible, especially when it means exposing myself over and over again to his molecular and psychic residue on her and having everything I put into my relationship with her go to maintaining its existence in the face of his onslaught instead of go to strengthening and nourishing it and making it deeper and more meaningful.
Yet. You are here. You admit to reading poly literature. Why are you so drawn to it if you abhor it so?
Sometimes what we abhor is a fear overlying what we are deeply resonating.
Just food for thought.