Just a thought, forgive me if it has been used here before:

“Shyness has a strange element of narcissism, a belief that how we look, how we perform, is truly important to other people.”

Reading this some months ago really helped me stay level headed. When you are at a club or party and you look around the room, do you really find yourself caring what people are wearing, how they are dancing, if they look interesting, how they smell? Do you even notice?

Turn this on yourself, in the nicest possible way what you do and say isn't really important to other people. To believe it is can stop you from taking chances and it will fuel anxiety, making things out to be bigger than they are.

(I understand that shyness and anxiety can be much more complex than this, but I just wanted to share this thought, I have found it to be very calming).