What are you doing to start losing weight? You need to implement a healthy diet, keeping calories in check, with moderate exercise.
Most likely your parents (whichever one live with) buys the groceries, so ask them to help you and to make sure there are plenty of fresh, healthy foods to eat, instead of snacks, like candies, cookies, chips, etc.
Keep a food diary so you know how many calories/day you are actually eating. Also log your exercise, so you know how many calories you're burning. You have to burn more calories than to take in.