I feel left out (in many ways). Can you guys recommend me some books to help me walk through it?

I’ll just start by saying i’m already in therapy!! It’s great. But i just want to read a book that can help me walk through this feeling of being left out of all social groups.

It goes from people im close to, all the way to people ive barely talked, but for some reason feel left out when i see them hanging out (don’t ask, if i knew why it wouldn’t be so hard/confusing 😅😅). But at the same time it just feels so childish, all of it.

So i want some recommendations that can help me fully realize/accept that the world is so much bigger than just a friend group.

So yeah, a book recommendation for a young adult girly feeling left out. Maybe something related to stoicism? I don’t know, but i’d love some help!!