Can anyone identify this health issue for me?

You most likely have a cold. Sleeping with your mouth open (lots of people do) causes you throat to feel "dried" even though the mouth is not. Saliva seeps though the tongue and mouth tissues. Brushing your uvula could be the problem. You irritated it. I'm surprised you didn't't gag yourself to death - LIL. Hot tea, Bourbon, or just plain hot water...mixed with a heaping spoonful of honey will help sooth the irritation. You're swallowing a lot is because the throat is looking for "saliva".