I have under 1 thousand cals per day worst 1200 exercise at least twice a week and not lost weight for months?

Eating too little: When your calories don't exceed your intake by much, you r forcing your body to go into a starvation mode to hang onto every little calorie it can ; become like a camel. Best to get your metabolic engine running, and eat healthier choices, hydrate well, especially while exercising, and have a good, balanced diet, so you can start burning those calorie logs, instead of keeping them on slow simmer.

You may not be: Eating enough. As strange as it seems, - sometimes eating too little over a period of time can cause you gain weight more easily. Your body goes into starvation mode ; your metabolic rate drops. Consider working with a nutritionist.

See your doctor: You have had lots of tests. Consider help with coping and organizational skills. Increase time efficiency. At your age you need to be actively exercising more than twice a week, and not just walking. Consider getting a trainer or joining a soccer team, basketball team or something that actually burns calories that you would enjoy. Get help with accuracy in calorie counts and food portions.

See doctor for: Evaluation, do not go below 1000 calories or you starve yourself hindering weight loss. Also make sure you don't skip meals as this hinders weight loss.

Consult a nutritioni: We really can not answer without knowing how much you weigh, what your bmi index is and how you count your caolries and what kind of exercise you do and your life style i will suggest get a baseline check up by your doctor including blood test for thyroid consult a nutritionist about your diet, how many calories and source of calories exercise at least 4 times a week on your own or with trainor.