blood-sugar, diets, what is up with me?

I am trying to figure out the cause of why sometimes I feel dizzy and/or nauseated and/or shaky. Most of the time is all three together. My #1 suspect is that I'm somehow not taking in enough callories/sugar or am hypo-glycemic (did I even spell that right?). But... just to rule out whatever I can... I am going for TWO whole weeks with absolutly NO DAIRY at all. Then I'll eat cheese and ice cream again and see if there is much change in how I feel. I will repeat the same experiment only with wheat/gluten. I think that will be very hard to do as well. I love my dairy and wheat! I don't even have very much - it's amazing how that little teaspoon of ranch or those two tiny scoops of ice cream - that one little square of chocolate I break off once a week - can be missed so much. It's only been three days and I am 'surviving' just fine actually. At any rate - today I got the "dizzy" spell again (not on dairy, mind you - and while very hungry). I got a GREAT drink from Juice-it-up with some berry from Africa in it (which is supposedly better for you than blueberries even) - it was so amazing! No dairy in it, mind you. Plenty of sugar and I felt so much better after drinking it. The shaking stopped nearly 10 minutes after. I'm really starting to think it has something to do with blood-sugar levels or something. I need one of those little devices that pricks your finger and measures your glucose levels. Thanks for your prayers. I don't think this is a big life-threatening deal but it certainly is frustrating and a little scary when you're standing in the smoothie line and you think you are seriously going to pass-out.