It sounds like you have an EDNOS (eating disorder not otherwise specified).

The only thing that is going to help you feel better about the way you look is to see your doctor or a therapist (possibly one specializing in eating disorders). Anorexia is a grizzly nasty disease that if it sets in will steal your personality, your friendships, possibly your relationship or even your degree/career- it is really not worth persuing weight loss when you already have a BMI of 18 (20 to 25 being the normally accepted healthy range) but you almost definitely need someone to help you to feel better about yourself, your appearance and weight