Are you taking any medication for your depression/social anxiety/panic? Are you still seeing a psychiatrist? I found that after I stopped drinking that dealing with my underlying bipolar disorder was a huge part in remaining sober.
I'm an extreme extrovert and found it difficult to get comfortable at my early AA meetings. What you're experiencing is not pathological or even uncommon. It's totally fine to be quiet and listen for a time....eventually you'll organically and increasingly interact with people. Give yourself the space to be shy and allow yourself time to get comfortable. Also remember that you can always pass if it's your turn to share and nobody will judge you. We've all been there!