I am in a somewhat similar situation to you, at least emotionally. I've tried a lot (therapy, sex therapy, somatic experiencing, IFS, IPFP etc) to give myself the validation I was lacking in my relationship but ultimately feel like I failed. I now got the validation I was seeking so desperately outside of the relationship and it's the best feeling in the world to me.

I can't yet say yet whether getting that validation from outside is healing anything, or building my confidence in this regard, I definitely hope so. But I can say that while I believe this "it all has to come from within" to some extent, I just couldn't, and I tried very hard for quite some time.

At the end of the day, we're humans, evolved to be highly sensitive to social cues, with needs we can't always satisfy on our own. That's why we're in relationships with others. Often I find that getting other emotional needs met is considered OK, like closeness, affection etc. But why is it not fine to have sexual validation as an emotional need?