It's okay to make mistakes, that is what makes us human beings. And don't worry about what your manager or other ppl think about you, what matters is what you think and feel about yourself. Don't beat yourself up everytime you make mistake, tell yourself that it's okay to make mistakes. About social anxiety, maybe you can start with a small group of friends around whom you feel comfortable enough to talk. Just one or two. I started with opening up to one friend and it was a lot tougher but now i'm pretty okay dealing with people. You just have to be yourself and not worry about what they are thinking about you, or what they are judging you for, coz we can never know what is going on in their minds and it doesn't matter what they think. Just be yourself, if you are being yourself, some may like you, some may not. It's not in our hands who likes us and who doesn't. Be with those who like you for being yourself and you'll slowly find the anxiety reduced. I know how it feels, but if you stop wondering and worrying about what others think about you and be yourself, it will be okay eventually. :)