First thing, you need to lose weight for yourself (not mom). It has to be something you really want, because a lot of losing weight is being ready mentally. Look around and find a plan you might be able to follow or find a caloric calculator that can help you decide on a healthy caloric intake for each day. (You can google "calorie calculator"). Then the hard part begins (following your diet plan). Start getting in some kind of exercise every day. Do what you need to do to make yourself happy and don't listen to anyone's negativity. Then might mean well, but it won't help you. Good luck and I hope you enjoy school.