Yeah, I agree with the banana comment. Or sometimes I make my own latte- use milk and water and add some coffee. Seems to give me extra energy

Also, since you are doing p90x, you may want to increase the servings of carb? Add one a day? Or some fruit? You are doing an intense exercise that tends to be for bulking a bit so your body may be asking for extra glucose as glycogen stores are being depleted.