I can't diagnose but to me it sounds like a social anxiety, those are a lot of symptoms that I have and I have social anxiety too. Just the general fear of making a fool of myself in front of people scared me, or anything that included my involvement in a group or social interactions. I hope that you find the help that you need, I encourage you to reach out for help, I used to be terrified of opening up to people (still am in some ways), but after I did recently I am slowly realizing its the best thing I've ever done.