It could also be a BP support group.

Just two buts: you don't want to concentrate only on your problems, so if you meet someone nice there, get out of there to just talk casually about all sorts. Also be careful that you don't get romantically involved (for the time being, while building confidence (back) up) with someone who also has a borderline personality (I do, so I feel I may say so), because it can be explosive and really hurt any new-found confidence. In my experience, BPD that hasn't been attenuated by the years and insight can only be handled right by someone with at least some borderline personality tendencies. It will be explosive, but stuff cancels each other out as well. For people with social anxiety it can be traumatising without a BPD outlet: very debilitating at your first try. You might never try again.

If you are to go to a support group, maybe make friends with someone a bit older maybe with a bit later-onset mild, classical BP. Maybe someone with social anxiety themselves may also not be your best bet. But who knows.

You could even start by talking to strangers on public transport or on the street. Seriously, maybe have a good chat with someone who is homeless. They tend not to have many people being kind to them or that listen to them, while you might have more in common than you think (you having BP, this is not at all unlikely).

Good luck! Be sure to keep coming back here: we are your friends too.