TeJeKo, this forum isnt really for sex advice per se. But most of us here really like sex, or we wouldnt be poly, b/c sexy feelings are involved with exploring multiple partners!
I know youre in therapy and it's apparent you have low self esteem and bad feelings about your body in general. How it looks, how it works. I am sure that's affecting your ability to orgasm with your current and past partners.
The advice here has been mechanical. Touch here, touch there, clit, gspot, vibrators, etc. This article addresses the mechanics as well as the emotional component, which seems to be your main issue.
I am sure, if you continue with therapy, your self-love and life in general will finally improve over time. Your sexual response and abilities will come along with that.