Thank you so much for writing. It takes courage to face up to a problem that feels as random as this one. The good news is that you have managed an eating disorder before. The best predictor of whether someone will succeed in regaining health is whether they did so in the past. You did. You will do it again.
Although you managed to stick to a diet the doctor gave you, you did it because you didn’t want to disappoint your parents. You didn’t have help dealing with your own feelings about your weight and food. You were bullied at an impressionable age. Their taunts took root in your psyche and you have been struggling with them ever since. You need help getting those negative judgments about your appearance out of your head.
Please, please. Talk to your folks. Believe me: They would rather help you with this problem now before it gets any worse. They would much rather help you see a mental health counselor than visit you in an intensive care hospital unit because of over-dieting.
It might help you talk to them if you just shared your letter and this response. Then make an appointment with a counselor who has experience with working with teens with eating disorders. Your medical doctor can help you locate good help.
I wish you well.