Jelly, I think a fair answer to what I think is your main question is that what you are seeking, in terms of help, probably doesn't exist. This is why "therapy" has been so frustrating for you.

Becoming socialized to where a person is at ease in connecting with others is like learning a language. You picked up English as a child. You just soaked it in, without having to really think hard about it. If you were to try, as an adult, to learn a second language, you would have to put in an enormous amount of work to do that. Even then, unless you went and lived in a place where everyone spoke that language, learning it would be awfully hard. You could take high school and college courses, but that would be frustratingly slow. Same with learning socialization. To try and sit someone down and "teach" them how to socialize is about as hard as teaching someone a second language. You sure can't learn either by showing up at some professional's office to be given "tips."

You basically have to teach yourself. I admit that's hard.