How to stay CALM before solo!!?

I have a piccolo solo at the very beginning of a song that my band is performing at a very big concert with a very big AUDIENCE! it would be my first time doing a solo in front of a big crowd and everytime I play my heart beats fast and my legs go NUMB >< any tips to keep me calm and to stay thinking positive??? also, any tips on getting the piccolo to sound more in tune? and how to not sound airy?? i would really appreciate the help! the concert is this WEDNESDAY. Thank you so much. :)