@runner61627, my experience was similar although my radiation was aimed more toward ear than mouth. The associated burns healed slowly. When I had a worsening of pain and irritation, it was diagnosed as a fungal infection and treated topically. I had been using Magic Mouthwash from the doctor but I needed a stronger antifungal. Four weeks is right about when I started to notice an improvement, and like Wm said measuring it week to week is better than day to day. I used and oral lidocaine gel applied with a Qtip on the sorest spots just before eating. This is a miserable time, but you will get through it and food will eventually taste good again. Be strong.