I have no words of advice, sadly... but I can empathize as I'm dealing with jealousy myself, and it makes no sense to me that I feel it... but like you describe, it's tied to my own feelings of inferiority
I also run through scenarios in my head, and I hate it. I put myself in therapy to help deal with it. luckily I have access to therapists who are poly and queer supportive. I wouldn't want to have to deal with a therapy relationship in which I wasn't fully accepted.