Sorry you feel like that.
Do you feel nervous when you see that you can't contribute in the topics? Bc if not, it's sometimes good to listen and learn from them.
Do you feel the same in any group or were there people you felt that you could share more with?
Is it a question of topics or that you feel inferior in relation to them?

I also always feel like an outsider so I only have questions for you, sorry.
I can tell you what I do when I'm force to be in a group.
When I'm not nervious and go to the bathroom, I try to listen and make an effort to go into the topic they are talking about, often by making them questions. I try to do the very best to avoid being absolutely silent ( I feel very bad when I'm stuck- this is the time when I make an excuse to abandom the group for a moment and try to calm myself down) or calling the attention bc it's too much pressure.

Sorry for the long ().