Many medications, including over the counter stuff, even cold meds can cause dry mouth. Are you taking anything at all?
I'm a 10 year MAV sufferer (chronic migraine condition) and take a daily med that cause dry mouth as a side effect and I already drink tons of fluid before I began
vaping. Since vaping I noticed a slight increase in my fluid intake but nothing insane.
Anyways, my point is there is hundreds of medications out there that can cause dehydration symtoms like dry mouth and may not be vaping related at all. Medications include cold, depression, pain, anxiety, antihistasmines and decogestants.
I personally think you should see a doctor as health is nothing to mess with and no one here is a doctor and even if some here is, they cannot examine you online lol