I used to get terrified beyond belief when I had to present something in front of the class. I'd cry, shake, get bad diareha, have stomach aches, puke, the whole 9 yards. Then I took an English class in which my EVVVILLL teacher made us do that kind of thing monthly, for 5 minutes at least.
I got over it in about 3 months. I thought he was awful at the time, but I can't thank him ENOUGH. In my Senior English class, I can now give speeches without visibly shaking or getting worked up, stuttering, ect.
The best thing to remember is that everyone else has to do the exact same thing as you, and so will likely relate to you in some way. Unless you do something like faint, nobody will really care, so you may as well make it as best and overblown as possible. Try to act casual and "light conversation"-esque. Make sure you act flexible and behave as if you are talking to a friend.
Those are tips that helped old social phobic me, so they could probably help you, too.