That means you'd have to lose 40 lbs in just 3 months; I don't think you can do that safely. Safe weight loss is 1-2 pounds/week. The first thing to do is stop eating all junk food, such as chips, candies, sodas, pastries, white bread and regular pasta, etc.
At age 16 your body isn't fully developed, so you have to be careful of losing weight too quickly. When you eat, make sure you fill your plate, mostly with veggies (no butter, sauces, etc), smaller portions of lean protein, and even smaller portions of whole grains, such as whole grain bread or pasta.
Limit fruit juices and opt for whole fruit instead, because whole fruit has lots of fiber, particularly, apples, pears, etc.
I don't know how often you play softball or soccer, but you may need to add other types of activity, as well, because once your body gets used to doing the same things, it doesn't burn fat as efficiently. You might try going for a brisk walk every day, look into yoga, zumba, etc.
You should also have your thyroid checked to make sure it's working properly. Hypothyroidism is a very common cause of weight issues and should be ruled out before you begin a "diet".
Ask to have TSH, Free T3 and Free T4 tested.