I think in every friend group I've been in, I've always been that person on the outside looking in. Tolerated, but never celebrated.

Stop doing it to yourself and others .. find your tribe and allow them in.. don't expect forevers be there at the moment. Accept what you're given, appreciate it.
Appreciate yourself, it's the only way .. show actively your appreciation towards others. Sometimes by giving, you receive. Give what you want to receive...
I'm talking to myself too, along with you ! :)