My partner (27M) and I have been together 5 years, open for 3, 6 months ago he started dating more seriously.

He met Sarah (20F) a month ago, kind of in NRE (texting a lot, sleeping over 1x a week, date nights here and there). Not necessarily poly, for now I'll say non-monogamous.

I have dated way less than him. I have not fell in love with anyone else, I'm so in love with my partner. He's the only person I want to date and have sex with. He's my world and no one else compares.

Obviously, it's been hard seeing him get involved with someone else, because I can't relate to what he's feeling. I just know I get less time with the person I love whom I've been monogamous with for the longest time (the first 3 years of open we were swinging).

It's hard to sleep alone without him, to have less sex with him because he gets some else where. Our relationship was struggling. We were not dating because we got together a little before the pandemic and have very little money so we always decided to stay home and watch movies. Never got into dating so it's not really a habit. Now that he dates her, I want dates too, but it's not natural for is to actually do things together.

He has dated quite a lot and all the girls he has seen orgasm quite easily. He can make them cum every single time while I cannot orgasm during sex. Only laying on my back, eyes closed, dirty talked, touching myself. So he's technically not making me orgasm. I feel incredibly incapable and boring, it's the same every time, but that's the only thing that I found that can make me cum. I don't feel attractive to him.

I've been struggling with my self-esteem a lot for the past years, even more recently due to the changes in our relationship - and him giving more attention to someone else. I feel ugly, stupid, have no knowledge on things, timid and submissive.

How the fuck can I fix my self-esteem issues once and for all so I can move on with my life and actually live?

Thank you!