It sounds like you're experiencing periods of hypoglycemia...this happens to me sometimes, but usually only when I eat a lot of carbs (especially non-fibrous carbs) in one sitting and then don't eat anything for a little while after that (like on a cheat day after a breakfast of count chocula and nilla wafers). This is because insulin levels rise in response to a high carb meal and then fall off sharply a few hours later. I don't really know if this is your problem, especially since you're not eating refined carbohydrates and you're eating 6 meals a day...but if it doesn't get any better, I would try to cut down on carb portions in meals...like, only eat 1/2 cup of oats in the am, and only half the pita bread or something ( is this pita bread whole wheat or white?...the more fiber it has, the less chance there will be for it to cause an insulin spike). Also, make sure your meals are evenly spaced and no more than 3 hrs. apart. Again, I don't know if that has anything to do with it, but it's a possibility.