HELPP!!!!!!!!!!!!!!! am i fat?

I do ballet and everyone is so skimpy and slim. I feel like a fat little plump in a stupid little leotard which my dance teacher forces me to wear. Im not overly fat yet i would like to loose some kilo's. I do like 15 hours of dancing a week i expect myself to be more slender. I dont eat extremely healthy but i do have 2 fruits and 3 veges a day. help how can i loose weight?