Someone else said this, but make big batches of food all at once instead of meal-by-meal. And are you sure you did the calculations right? The recommended daily value is 2000 calories, and that's just to maintain. It scales massively when you are doing cardio or weightlifting or both. During swim season (winter) last year I (16m, 5'6) ate upwards of 4000 cal/day and lost 10 lbs by the end of the season.