If you have a minimal or no appetite, and you also want to stop eating soon after you start -- you feel full quickly, then that is a sign that you really do need to go visit your gynecologist. Especially that you are losing weight but not in your abdomen area. Don't be shy or hesitant. I don't want to scare you, but take care of your self and go to the doctor. Get an appointment right away -- don't accept a delay from the office staff! Good luck, and take care of yourself!
I had the same experience when I had my cyst. I had virtially no appietete at all. I would have a couple of mouthfuls and I just wasn't hungry. I put it down to the fact that my cyst (35cm) was taking up all my room that I had no room for anything else! (Which was quite a pain over xmas!) I'm not really sure why I was put off food, if it does get serious I would say you should ask your doctor for infomation and if it is quite common. x