Yanno, the best thing you need to do is be absolutely proud of yourself. You got up there and DID IT! , The second thing is NOT to smoke, it makes it worse :) thirdly once again be PROUD of yourself, you have accomplished something wonderful tonight, Even though u felt like it was the end of the world you still got up there and did it. That should make u feel wonderful!! Apple juice is a Natural Calming Solution and so is a lil bit of chocolate. As for the rest of the anxiety, Just calm urself down, give urself some things to do to keep busy, but keep thinking how u did this and u got through it and u did it well!! Congrats I am proud of you.
Breath into a paper bag or just do some breathing exercises. Walk around. Drink some herbal tea to calm down.
up your protine intake that might help.