trying not to deviate from your original diet too much:
breakfast- 5 whole eggs, 100g carbs (oatmeal, cereal, bagels, toast is fine), 3 slices turkey bacon, fish oil
lunch- school lunches (just eat whatever high protein, moderate carbs, moderate fat you can)
pre-workout- 50g whey, 100g carbs, fruit
post workout- 50 whey, 100g carbs, fruit
dinner- chicken/tuna/turkey/beef/fish/whatever + 50g carbs + veggies
last meal- 1-2 cups cottage cheese + nuts
granted this is just a rough guide, it will put you in the right ballpark for all your macros . protein intake is higher than you originally outlined - both from increased protein sources as well as tag-a-long protein youll get from your carb sources. fat intake was never a problem with your original diet (depening on amounts) but i got rid of the flax since fish oil is a superior source and too much flax can cause problems. this diet also isnt set in stone, its a working model. if you find youre losing weight or not gaining, youll need to eat more. if youre gaining weight too fast (which i doubt will be the case) you eat less. youll have to figure that out on your own and tweak from there.
remember, youre an already big boy whos trying to get even bigger - you need to eat. your maintence calories are somewhere near 3,000. in order to grow youre going to have to eat about 500+ calories on top of that (depending). With what I assuming are hours-long, pretty brutal football practices, that number increases even more. I wouldnt be surprised if you needed upwards of 4000+ calories to actually gain weight with that level of activity.
if taking in that much food becomes a problem, theres always fast food, and weightgainer shakes (think protein powder + ground oatmeal + olive oil. a lot of easy calories).