Too many carbs??? I eat 10-15 weetbix!!!!

Bezza743

Is eating between 10-15 weetbix per day too many...? i am a 17 year old male, 73kg and am 189cm tall. i usually eat between 10-15 weetbix (also known as weetabix in the US) a day but can sometimes eat as many as 20!!!! i usually eat 5 per sitting usually eating 1 bowl for brekkie, one bowl when i get home and one after dinner. i still eat other food during the day such as sandwiches and fruit etc and drink roughly a litre to 2 litre of water a day.. is this too many carbs? one serving of weetbix (2 biscuits) is just under 500kj, so eating 10 would be 2500kj and 15 would be 3750kj. this is of course w/o milk added yet. am i providing my body with too much fibre? somedays at night i have stomach cramps that range from mild to moderate discomfort. could this be from too much gluten, too much fibre, or just too much food being in my stomach at one time? i love weetbix and think that they are a great cereal and i couldnt possibly see myself only eating 2-3 a day, i can eat that in 4-6 bites!!!!! as gross as it sounds but could tapeworms or some other internal parasite be stealing nutrients from my food making me more inclined to eat?
p.s - why is it that i can eat this much energy dense food throughout the day yet feel lethargic and tired? can too much food do this or could i have another condition that causes this?