I may be stupid and unevolved and old-fashioned, but I just don't see how polyamory works in a 'committed' relationship of any kind. Because, by definition, the relationship isn't really very committed, is it? I was with a woman for ten years. After seven, I discovered she had had multiple 'boyfriends.' Maybe she was polyamorous, I don't know. But I do know it did not work for me. I left and didn't look back.

I see a person--you--doing all kinds of mental gymnastics to make something work for your partner that most folks would not be willing to do. It's great that you love each other. But as smart people have said over the millenia, love is not enough. I wish you all the best and hope your pain ends soon.