Take some pressure off yourself. I know this is the most stressful thing ever, I went through it. But you also can't go into the audition thinking that it is the most important thing in your life. It's normal to be sickeningly nervous, but whatever happens in your audition will not break you. Things work out for the best, and there are always more than one way to get around a sitiuation. When I had to audition I didn't believe anyone who told me this, I thought they were full of crap, but I was wrong. Just something to think about.
"It's really crazy backstage. Just before the show started, Elaine Stritch got into a fight with stage hand, and then inexplicably started squeezing Hugh Jackman's buttocks. And by the time they had sedated her, she had punched out two cops and was holding Norbert Leo Butz hostage, threatening to kill one of his three names." -Nathan Lane