Just walk away. If you're not satisfied in the relationship, if you can't talk to them about the issues, if its making you feel worse instead of better about your life -- tell them you're sorry but that its not working out, and could you all just be friends (it sounds like there'd be almost no change). Your expectations are not too high, there are other fish, etc.
Me, 30ish bi female, been doing solo poly for roughly 5 years. Gia, Clay, and Pike, my partners. Davis, ex/friend/"it's complicated." Eric, Gia's husband. Bee, Gia and Eric's toddler.