Hi!
The best thing is to share your thoughts with an elder you can trust. You can speak to your school counselors. If you eat a lot, that is also an eating disorder, then you will not be skinny. Also, even if you eat less, if you eat calorie packed foods then also you will not be skinny. So, discuss all your problems with someone you are close to and who can guide you through this. Your school counselor would be able to help you tremendously.
Take care!
Eating disorders are a disorder of the mind, of our relationship with food, eating, and ourselves. They are often about control, and our perceived lack thereof. Weight is a side effect of this disorder, and it does not always accurately represent the degree of the disorder, or the danger you may be in with your health as a result. A specialist trained in treating eating disorders would be the ideal person to talk to, but I would start with your family doctor. He or she can offer referrals. There is a national eating disorders helpline, too: 800.931.2237.
It is possible to recover, I promise! It takes courage to reach out like you have here, and you should be really proud of yourself for taking that first step.