Solo & On-somble! I need some HELP! ?

Ok. well i signed up for my choir thing called solo's and on-somble. i sing alone in fron of a judge ECT. well i have to wear a dress. im not the biggest dress fan but i have to, well i wanted to wear a black dress {Long} with sleeves that go about half way down my arm. but my chior director wont let me. so my mom is gonna make me wear a black dress thats TOTALY COVERED in flowers. its little silver flowers. i tried it on and i looked like a 40 year old thats stuck in the old days. i told my mom but she said she wont let me wear my other one because i looked good in the other one. Well i get NERVOSe really easy. and i get even more nervous if i dont think i look good. so does anyone have any pointers about how to be LESS Nervous and about the Dress??? If so thanx!!!