How can I keep my blood sugar from dropping during sleep?

4 reactive hypoglyce. Eat only meat or fish or cheese or eggs or poultry and low starch veggies, drink only water. In other words avoid all carbs, carbs will only briefly raise your sugar levels and then your Insulin levels. The fats in the meat or fish or cheese or eggs or poultry will act like a "log on your metabolic fire" to keep your blood sugar stable for hours without raising insulin.
Inadequate info. If you are diabetic, this may come from Insulin regulation. If you are not diabetic, my guess is that you are very fond of sugar. Oddly enough, sugar causes low blood sugar because it excites Insulin release. See my blog, "oxygen, the spark of life"--- tough reading because it is educational. You can google it.