I relate to what you wrote about feeling anxious about making connections, and joining social groups/interactions.
I have recently thought the same thing, "maybe I should just close myself off to everyone?". But, as I read your message, I felt inside of me that it might just hurt more. We all need to feel that we are loved and appreciated. Just be kind with yourself and take it one step at the time. If you feel too anxious about joining an activity, then maybe do something smaller. But should always be something you feel capable of doing / comfortable with.
Feel free to message me if you want to talk further.