Wow im fat?

im 13 years old a male 61 inches high and weigh 130 pounds last week i weighed 128. my waist size is 38 inches. im gaining weight really quick, i dont know why either. I love eating chips ahoy cookies(Chewy) i can eat like half a pack in one setting. i do eat a lot, in fact A LOT. and im just blowing up like a balloon! My doctor said you better exersise but i dont feel like it, instead i eat. What should i do?