I'm sorry i'm only 17 and a male.
The reason ya wont be losing weight, anyone for that fact, by just dieting as that is removing, lets say, 1/4 of what your body needs, so your body stores up on what your 'cutting' from your diet, so that goes to fat.
To lose weight, ya gotta cut the bad food from yer diet, eat mroe healthy and excerise-thats the big factor.
Throwing up is bad, because when you do eat food and don't throw it up it will go straight to fat and then chances are, you'll feel worse-this becomes a rather bleak downwards spiral.
Please don't do this to yourself.