For very small glucometer, there is a disposable meter that is built into the top of a black vial of test strips. I think the brand name is Relion (normally one of the least expensive brands), but I'm not sure. Walgreens carries this product. The One Touch Ultra min that princesslinda mentions fits in my purse, too, and I carry a small purse.
For the near future---f you want to eat dairy to curb your appetite you can go lower carb than yogurt. Yogurt is not normally "completely" fermented, meaning that not all the lactose as been eaten by the bacteris that make the yogurt. However, you can get cheeses that are nealry completely lactose (that is milk sugar) free. Look on the back of packages for the carb counts and you should be able to find some with fewer carbs than yogurt. If you want to stick with yogurt, the full fat yogurts are almost always fewer carbs than low fat yogurts.
CARBS: Carbohydrates in Yogurt
By the way, many people would not consider 100 carbs a day to be "very low carb," but moderately low carb. If you are determined, you can get by on maybe 30 grams of carbs per day, and still eat vegetables and cheeses, even your small yogurts, etc. You would have to pay close attention to carb counts to do it, though.
One doctor says that when a cause for high blood glucose is not obvious it is very often related to a dental infection. Keep that in mind as a possibility.
Also, double check to make sure your strips are not way outdated and that your meter is correctly coded. Both these problems could give erroneous readings.