Jenn, I think what you're describing in terms of pain is undermedication at night. I suggest you take the two percs at bedtime and also at your 1:00 dose. If you try to take your dose early, that's really not going to fix your problem other than just that one time. That's not what you want. Remember, you are still very early in this recovery process and there is nothing wrong with needing that extra boost of pain medication to rest at night.
Try that for a few nights and see what happens.
As for the food, how about some supplement drinks like Ensure? They are a great snack with lots of protein. Your body may need additional nutrients right now, so eating more frequently is fine. You definitely don't want shaky feelings! That would seem to indicate a drop in blood sugar. More protein at regular intervals should keep you feeling better.