Spider - yes, that was one of the first things that hit me when Sjogren's hit bit time. I was so dry and thirsty all the time. I found myself guzzling anything to drink.
After a few months, I realized that it wasn't that I was thirsty, but that I was so dry. The dryness, arthritis flares even where I previously had none, fatigue and brain fog told me something wasn't right.
After reading up a lot about Sjogrens - and from this site, I realized that I needed to stop drinking so much all the time. Now I take sips, suck on hard candy, and chew gum for my dryness. I've read that drinking too much all the time can actually take away the good enzymes that what little saliva you do have left provide.
I'm glad you're getting your blood sugar checked, because you never know, and there can be over lapping symptoms.