Hi @darapoza,
I had 35 rounds (7weeks) of Photon radiation for a total of 70Gy and 3 rounds of cisplatin chemo for tonsil cancer back in 2008 but no surgery and to help with the brutal dry mouth tried electrical stimulation acupuncture in 2015 which was offered at my cancer clinic for head & neck cancer patients. I was tested to get a baseline and retested after 8-10 appts. and had great results. Never needed to go back and to this day 10 yrs later dry mouth is a non-issue. I also slept with a bottle of water next to me and got a Humidifier on my end table to make sure there was the most moisture possible in my bedroom to help get some sleep.

I got this from my other cancer group SPOHNC and it mention AQUAx2 which is a clinical research study for people with moderate/ severe dry mouth (xerostomia) caused by radiation therapy purpose is to assess the efficacy and safety of "gene transfer" study drug called AAV2-hAQP1.

In addition,I didn't have this available to me but others on this support group site have mentioned “Xylimelts Stick-On Melts” you can buy off Amazon and the box of 40 was less that 10 bucks. People say they really work, and they sleep through the night. And their daytime dryness is much better also. You should research using for extended period of time effects. Also, Biotene spray is effective long time after 2 or 3 sprays! And more recently there is a Aquoral Protective Oral Spray- Dry Mouth Relief which is more than temporary relief of dry mouth. Or a prescription of Cevimeline.

Hope this helps and you will get better. Good luck on the journey.