You guys are different. You have fundamentally different aproaches to how you love and need that love returned to you. There's no right or wrong here and don't expect either of you to truly understand the other. I don't understand how poly works internally and I don't think RP understands how monogamy works internally. I'd say it's time to move on for both of you. You can't show her love the way she needs it and she can't show you love the way you need it. Short term pain, long term gain...both of you will likely be a lot healthier.
Playing the Game of Life with Monopoly rules.
Monogamy might just be in my genes
Poly Events All Over