I can't help you because I'm struggling with ED also, but, you can't purposely choose to develop anorexia. trust me. you can try stop eating all you like but eventually you will get so hungry you will binge all out.. go back to purging or exercising whatever.. and start the cycle again. stick to the diet plan your program would have suggested.. your metabolism needs to find the 'set point', and where it adjusts naturally, and, eating the right diet will neither gain or lose weight
if you really want to lose the extra pounds FIND that diet and reach the set point, then think about incorporating some healthy levels of exercise. health and happiness over the struggles.