Deb,
I have had radiation and feel very lucky at how well my body is healing itself. There is some saliva production, enough so that I don't carry around Biotene spray or water with me everywhere anymore! And this is at only 3 months out. Remember, healing from radiation is different for each individual.
I definitely still have some side effects like taste impacts and some tightness of the jaw and some soreness of the throat but I am very grateful for what I consider to be a quick recovery. While I appreciate and understand your reticence to undergo the radiation treatments I would implore you to proceed with the recommendations of your doctors. Radiation treatment sucks. However I not only survived, but am now thriving. I am getting better and stronger every day. Life is good.
When do you get fitted for the mask? Are you going to receive your treatment at a comprehensive cancer center? I assume it will be IMRT? As a tip, my Radiation Oncologist at Stanford suggested I have the metal fillings in my lower jaw replaced with resin prior to radiation treatments in order to stop refraction of the beams and resulting damage to the tongue and mouth. While not permanent, apparently this additional damage can greatly contribute to discomfort during treatment. I was lucky and did not have mouth/tongue sores and think this is at least partially attributable to the filling replacement. Also, I subsisted on Skandi shakes almost exclusively during the hard phase of treatment. This is a brand name that I blended with protein powder, strawberries and yogurt in order to increase the calorie count. I would then plug my nose and force myself to get the calories in my body. Again, the hardest part of treatment only last a number of weeks. Please know and believe that you can get through to the other side. I am an example and I have made several acquaintances that live near me who have also finished the treatment and are living full, happy, normal lives.
It is natural to be afraid but hang in there.