NONE OF YOU FOLKS ARE HELPING.
Ribbons, if you are 5'2" and ~ 130 lbs, you're not about to die. It's a healthy weight. But you should ask your mom to make a doctor's appointment. The doctor probaby can't fit you in until after your exams anyway, so it's okay to make the appointment now.
You may think you're "fat," but you should be checked out to make sure you're not malnourished. Anyone can suffer from malnutrition -- in fact the very obese are probably in far worse shape. And your binging/fasting cycles are wreaking havoc with your brain chemistry.
If your exams are next week(?), then take your exams, see how you do. If you need to repeat a year, it would likely help you to get into uni better than if you try to force it with the grades you have.
I think it's VERY encouraging how quickly that you have warmed up talking on the internet, and how insightful you are about yourself. You have a conflict, and you are aware of the conflict. That's a solid accomplishment. While your mind clearly has anorexic tencencies, it looks like all of that "horrible" binging has keep you at a decent weight!
I would like to see you be able to Eat Without Freaking. If the best way for you to Eat Without Freaking is to count 900 calories of good Primal food, so be it. Even those 900 calories, especially the Primal kind, will heal your brain a little. (you WILL need to ramp up later, but you have to start somewhere)
As for losing the weight, this needs to be watched. I can guess what your ideal weight probably should be, but I'm not going to say what it is. I'm afraid of what happens if you lose some weight. Will you go back into fasting to lose more... will you never feel thin enough and keep losing below what you should. That's where the danger lies.
5'0" female, 42 years old.
Started Primal October 31, 2011, at a skinny fat 111.5 lbs.
Current weight: 101.5. lbs and holding steady. Spring yardwork here we come!
Co-worker 1: Needs to lose ~50. Now he wants to start Mayo Clinic Diet. Yeesh. Give it up, man.
Co-worker 2: Needed to lose ~55. Lost 20 from stress. Started Primal in Sept, lost 20 more, but gained 10 back on a carb spree. We're working on it.