I know what you mean: people talking about things they have in common bc they know very well each other, people talking about the interesting people they knew last weekend...i know it very well.
That's why I see AvPD how feeling an outsider.
Said that, there are other good qualities a person has and you can enjoy them and offer them to people you know.
The first step is acceptance. You reached a point that you were able with the resourses you had, now a new life is waiting for you.

I'm not going to therapy now. Terapists considered me a basket case. Lol!
I'm kidding. I was treated by some therapists and to be honest I'm very gratefull to all of them. They worked with me what I needed in each moment.