Do not worry at all. You dont need a psychiatrist
as you yourself are aware of what is wrong with you. First get the concept clear, the calorie requirement per day is 2500-3000 kcal for one person. You have not mentioned your age, but you said you go to school. Its very early for you to think of weight loss
If you want to loose weight go systematic:
1.Only diet control is of no use for controlling weight. You need to get involved in physical activity like jogging, cycling, swimming, skipping,rowing etc. Play outdoor games that is the best way you can get back to your health.
2. Break and take your meals 5 times in a day. This will increase your BMR(basal metabolic rate
) and you will digest things fast, and put on less weight.
3. Reduce fatty foods like bizza/burger/cheese etc.
4. Dont ever skip your breakfast.
5. Dont consume carbohydrate
6.Have lot of green vegetables/fruits/sprouted vegetables in your diet.
7. Since now so many days you arent eating properly take vitamin, iron and calcium supplements
for atleast 3 months to see instant results.
Stop thinking and start with a great motivation towards health. You soon will see the difference.
I hope this answers your question.
Wish you a good health.