The "first step" is admitting you have a problem, right?
Yes, that is true. And now you have admitted it to us.
Please help me!
What's the next step?
You should now see a doctor as soon as possible. You are describing a very serious eating disorder--Anorexia Nervosa with purging--you are both dangerously restricting your food intake and using laxatives and induced vomiting to purge food from your body. It is both a serious psychiatric problem and a serious health/medical problem--and one that should have immediate
medical and psychological attention and treatment.
You need to tell your doctor the things you have told us about your eating and purging behaviors and ask for a referral to a psychotherapist who is experienced in treating eating disorders. Treatment will involve helping you to understand your problems with body image, and other issues, such as your feelings toward your biological parents, that might be contributing to your eating disorder or other difficulties.
I cannot impress upon you too strongly that you must seek help for this problem ASAP. Your eating disorder is a symptom, it reflects the fact that you are in considerable psychological pain and psychological distress, and, in addition, this symptom creates even more pain and distress for you because you cannot control it. Your post here is a cry for help, and I take that cry very seriously.
In addition, your eating disorder can play havoc with your health and development, and it can inflict significant physical damage on your body. It is one of the few psychological disorders that can be deadly. Without immediate treatment, it can grow to be even more out of control, and it can lead to death.
So please, LexLake, I want you to see your family doctor, or pediatrician, as soon as possible, and get a referral to a psychotherapist experienced in treating your problem.
Your adoptive parents should also be made aware of your eating disorder, if they aren't already aware of it. You can delay doing that until after you have spoken to your doctor, because seeing a doctor, and getting a referral, needs to be your next step.
You are starving, both physically and emotionally, and there is no need for you to be in such pain. Help is available. Please take the steps to get yourself that help.
And, because I am concerned about you, please come back here and let us know when you will be seeing a doctor.