HELP! how to be fit and fab in less than a month?

ugh, i'm gonna be attending a hawaiian, sweet16 party this weekend and we'll gonna be like swimming (duhh lmao) i can't stop myself from eating too much carbs. so what can i do about it? how can i be fit and fab? people's first comment about me nowadays is that i'm getting fatter and fatter each day and it disappoints me. come on! help me guys! thankss :))