Help me i m stressed and nervous..wot shld i do?

i have this stress interview competition tomorrw and i dont tink i will be able to do it..i hav given my name to overcome my fear for it..but i regret doing it.i had participated befor and humilated myself terribly now i dont wanna go der and make fool out of my self and luk like dumb girl on de other hand i wanna overcome dis fear by doing good...but if i humilate myself again i wont b able to take it