Hi Michelle,
Mouth ulcers are very common during and after treatment. In my case, I had numerous white spots on my tongue and over the mouth. I used to look at my own mouth with a small torch every day to see if there was improvement. Sometimes one spot disappeared then another showed up. These I thought were ulcers that made me feel the pain when eating. They took time for healing and I still have sore at both sides of the tongue, which made me very sensitive to even the slightest spice put in the food. Other ulcers have long gone away. That should be the side effect of radiation.

Karen