I want to be thinner?

Every exceptional ballerina and swimmer and gymnast is so thin and beautiful. I want to be like that. Thin and beautiful. How can I get there? I want to be so thin that my thighs are super thin and then there's a bump where my kneecap is and then my calf is also thin. I want to be able to see my ribs. Please help! If you know of any way to lose weight fast, I'd greatly appreciate it. Btw, I'm 5' 1" and 90 pounds and I'm 16 years old. I WANT TO BE THIN!