Hi, Brett.
I have been having some luck with pilocarpene (Salagen is one kind). Talk to your oncologist or ENT about a prescription for it. Side effects (in me) seem limited to a little extra sweatiness, but I do get a noticeable increase in saliva. I try to take it about half an hour before meals to give it time to work. Also try the Biotene products, toothpaste, mouthwash, gum and mouthspray. They can help replace the enzymes in saliva that protect your teeth. They are available at pharmacies and some grocery stores and places like Target and Walmart.
Also try keeping a cool air humidifer in your bedroom at night, and ,of course, the ever present bottle of water.
Hope this helps a little.
Mike