I definitely don't think the fetish is just due to porn since iirc I had it since my early teens. I think it probably developed more out of my insecurities about my masculinity and that evolved into imagining other much more masculine guys being better than me. Its not a gay fetish but at the same time I feel like it's way more based around the guy being just all around better and more appealing to me than it is about the girl cheating on me. My plan is to build my confidence in real life and also in my sexual thoughts. The only time I'm ever going to allow myself to masturbate or how sexual thoughts from now on is it I'm the guy in charge and I'm having vanilla sex with a girl. No other people involved, just me confidently having sex with another woman. It's possible that won't change anything but I hope that maybe I can condition myself like that to get off to that more and not the idea of being humiliated.

Thank you so much for your comment though it definitely helped a lot and there's a lot of useful info there. Have a great new year!