You fell asleep on a full stomach. This is not recommended even for non diabetics, It slows the metabolism while you sleep, and your body uses the time to use proteins to repair the body cells rather than convert carbs. So your initial insulin rush from eating (first phase response) will peeter out with nothing to work on, your body will feel cheated since no glucose came through so your liver has a dump to compensate, then has another dump as your body prepares to wake up (dawn phenomena). Then you wake up, and start digesting carbs again, but this time there is no insulin response, so the [liver dump + dawn dump+new glucose] add together in a perfect storm.