Yes I had it. The doctor explained to me that the back of my throat looks like a skinned knee, so I could picture what the damage was like. Overnight there is a mix of blood, dead skin cells and saliva. Its not unusual for that mix to cause an upset stomach and vomiting. At the time I wasn't eating much and it was mostly dry reaching, so it was mainly saliva and blood that came up. Also the gunk in the morning also had some blood in it.

I recommend a humidifier if you're not using one already, and as mentioned earlier, ask your doctors next time you see them.