Your BMI is at 17.9, which puts you in the underweight category. I don't think you should be on a diet to LOSE weight. Really, you don't want to buy into extreme dieting right now because not only are you very thin, but you're also still in adolescence, where your body is growing as fast as it did when you were an infant. You need calories to grow, to maintain your metabolism, menstruate and to be able to have the energy to be a teenager.
I'm an RN now, and I've seen girls in your situation stop menstruating, collapse, and have to be fed through an IV. They're also harder to start and IV on because they are so dehydrated, and you don't want that because it stops your heart, and can cause damage to your liver, kidneys, and brain. Many anorexics lose the ability to reproduce altogether from decisions they make now.
I know, I went through a milder version of what you're going through now, and believe me, it's not worth screwing up your body because of the obsession. I was a plump child, and grew out of my shape into a very thin one, and I never wanted to be overweight again. But starving myself screwed my body up so bad that I was getting constant UTI's (they hurt like hell), I had no ability to focus, I had zero energy, I was passing out because I had a genetic anemia and anorexia exacerbated it, and my periods were always irregular and painful.
Please, eat normally during this time in your life. Worry about dieting when youre in your early 30's.
