Like Jessica, I too am thinking you should try a more substantial fuel too- try a hefty peanut butter & jelly sandwich (or two smaller ones) on multi-grain bread and a couple of bananas, maybe some fig newtons...dole it out to yourself during the ride, not all at once. Personally, if I used Gatorade, I'd mix it 1/2 and 1/2 with water and keep drinking all through the ride....but that's just me.
You haven't told us how old you are...? Is hot weather a factor here?