((((((((((( forgotten )))))))))))))

Do you see a therapist currently? Sometimes it takes several tries to find the right therapist for you, it is very important to be able to be open with a therapist. I really think you should tell a doctor or therapist about your obsession with losing weight, there is help out there. As far as your medication goes, it takes a while to find the right mix for each person and it usually takes working closely with a doctor or psychiatrist, while telling them exactly what is going on with you so they can help.
Keep trying, things can get better.