My suggestion would make sure to eat something before bedtime tonight (perhaps some cheese, or maybe even peanut butter as someone suggested).

I have had night faints before and yes they are due to an extreme drop in blood sugar. It is just your basic "fainting" spell and you had the classic symptom of the cold sweat (I went to the dr. for this). But that you woke up with it, and not woke up, stood up, have cold sweat, then almost faint, seems kind of strange.

Do you notice that you can't drink cold water on an empty stomach first thing in the morning? It causes something that can make you feel strange and even faint.

Try eating more for a few days and hopefully it will work itself out. Maybe even keep something at your bedside just in case.