Am i developing an eating disorder?

I recently started a diet about 3 weeks ago now. For the first week i ate so much food but ALL healthy. The second week i cut out carbs and 2 meals. This week ive just been eating bran cerial in the morning and a few friut. I am consistantly thinking about my weight and cry every day, i make sure i know what i am eating and how much, i feel huge even though people say im normal, i made myself purge 4 times, i have about 200-400 calories a day. And i cry when i eat some friut because i feel extremely guilty, am i starting an eating disorder?