To: Anorexia. Me: do not tell mom unless you are sure she is not part of the cause. Your probably better off reading books, learning an instrument. Use your mind because you have to center your identity on part of yourself thay can not be judged. If mom belittles your intelligence, keep your distance
Odds are your folks are well off and have to keep up appearances, and raised you to be seen but not heard. Build yourself up from the inside. Then you experience self respect and never look back. You will feel ungrounded at first, but fact of life, change can only happen outside your comfort zone. And dont tell mom unless you are sure she is not an accomplice, even unknowingly. I have seen this all too often with affluent families.
