Okay I will come out and say I have had an eating disorder in the past. I am at a healthy weight, but I honestly want to lose weight the healthy way. And only just 5lbs. But, I have been trying to lose weight on 1200 calories for 3 weeks and I have lost 1/2lb. That is ridiculous. Could it be possible that I have screwed up my metabolism royally that in order to lose weight now I have to go under the healthy 1200 calorie thing? I am a 22yo female who is only 5'1 and 103lbs. I just can't seem to lose anything.

No no no no don't go under 1200! The reason you would have screwed it up in the first place is because your body was in starvation mode. You need to fix it by eating small and often and eating more than you do, maybe about 1500cals with some exercise because that will increase your metabolism even more. Also if you're on a plateau exercise could help you break it :)

But anyway you're already close to being underweight I don't see why you need to lose any!

I agree with the other poster.  It sounds like your eating disorder is coming back a little if you are already so slim and still trying to lose.  You might want to look into treatment/therapy just to make sure this doesn't get out of control again.

I am not sure how you are taking in your 1200 calories... but it seems to work for me if you split that into 4 or 5 meals a day... according to my dad (who is a physician) this should speed up you metabolism... also you are 103 lbs. So you might not want to worry about weight and worry more about fat index...