As I prepare to meet my new students tomorrow (this will be the end of my 18th year), I'm frankly sick to my stomach. I'm the one in charge, yet I'm always really nervous about being looked at by so many new eyes and terrified they won't listen to me or do what I ask.
The thing that gets me through it each semester?
Remembering they are just as nervous to meet me and each other. 
So, next time you go into a new situation, remember that you are probably not the only uncomfortable one. It can help you feel less worried when you realize that everyone else is self conscious too.