I couldn't stand magic mouthwash, and tried to avoid it unless waas absolutely necessary. In hindsight, it was pretty dumb - anything that takes away the pain is good. You should rinse your mouth with salt and soda diligently, that helps quite a bit with sores. I would take magic mouthwash AND percoset about 15 min before my ensure meal, and that made it easier. I was in a lot of pain last couple of weeks and a couple of weeks after rad (I had chemo too, so that didn't help), and got more and stronger fentanyl patches as well.

Just try everything you can. But rinse rinse rinse. It helps a lot.

It's a long road. A little over a year ago I didn't think I'd make it through. You are young, and that's a HUGE plus. Hang in there. PEG tube is not the end of the world, but if that's what you'll need to survive, then go for it. I managed without, but I had lost a lot of weight, which worked out well since I was overweight to start with.