I think you best bet is to work this out with your parents and doctor. While losing weight may be a good thing, its important to do so safely and in a healthy manner. Increasing your intake of protein may not be a magical fix. If your current diet is balanced and fits your daily exercise, adding more or less of anything may not necessarily help. Most times, eating healthier will provide you with all the protein you need. Keep track of everything you eat/drink for a couple weeks, take that to your Dr, and chat about your need to modify or supplement.
Here's a few tips that may help without the need to chat with a doctor:
-Limit pop, candy, ice cream, juice, etc. One sugar snack a day is probably a good thing; but if you eat a piece of candy, a can of pop and a glass of juice on a regular basis, you'd be surprised at the difference cutting back can make.
-Eat three balanced meals per day, with healthy snacks in between.
-Limit TV/games/computer/texting to no more than an hour per day. Really--this is not only good for you body, but good for your brain and social life.
-Get out and play. Anything. Bike rides, basketball, tree climbing, skating, swimming, hide and seek... Getting out and doing stuff with friends and family should be a daily thing.
-Drink water. Avoid hydrating with sports drinks, juice, milk or pop. (Not saying milk with a meal is bad--just don't drink it every time you're thirsty.)