I need to loose weight?

Ok so im almost 13 5'7". 125 lbs. I need to loose weight because im doing alot of modeling and need to be a twig(: please dont judge! So i exercise alot. I run alot play volleyball bball and do cheer. And dont eat that much but have a tendency to eat chocolate. Ive lost about5 lbs this week by just not eating alot drinking water and looking at a picture of a supermodel when im hngry. How do i lose more weight fast?! Next fashion show in 3 mnths!