As others mention you sound like your carb depleted post ride and not topping up carb stores again soon enough .Like others mention go with some simple carbs immediately post ride and then add some complex carbs with the meal later.Also you want to insure your carb stores are fully topped up pre-ride and the oatmeal is a good source .Immediately pre-ride or during ride I agree light snacks or gatorade works for high intensity training and as mentioned don't overlook plain water for hydration.