I've passed my goal!! But cant kick dry mouth even though I drink water like crazy!!

 Well its been about 1 1/2 years since my gastric bypass and the Doc said I wouldn't probably see anything below 160 pounds....I was approx. 250 before surgery. I am happy to announce that I have gone down to 142 pounds...which I fluctuate between 142 and 145.  I have gone from wearing a size 22 to a size 8.  I have a little bit of sag here and there...under my biceps, a little on my tummy and I got a little bit of what I call "Saggy butt"  but you know. Ill take the sag over the fat ANY DAY!! And bottom line is Im a whole lot healthier!!  The only real thing Im stuggling with is the dehydration/cotton mouth I drink like crazy ALL DAY but sometimes I cant even swallow or speak as I have no saliva. My tongue sometimes feels like a cat's tongue...Ive tried biotene sprays/mouthwash/lozenges but this is SUPER BAD!!?? Im at a loss at what to do?? Any suggestions? I went last week for a blood draw just for good measure. Thanks