FWIW, I have pretty bad social anxiety, but I found it didn't interfere at all with voluntering with patients. It's different when you are in the role and have a reason to talk to people. And when patients are relying on you for support, it sort of snaps you out of your social anxiety. Somehow, even though I have terrible social anxiety with my peers, I come out of my shell and become really confident and sociable when connecting with patients. I found that volunteering actually helped me overcome my social anxiety a little bit.