I'll chime in on the guess that you may be dealing with thrush. Like Mark, my thrush didn't look like it was supposed to so no one caught it until I hit an osteopath on duty in the walk-in clinic. Nobody else, not the radiation oncologist or the ENT, figured it out; they just counselled me to be patient about my throat healing. After the osteopath prescribed nystatin, in one week I went from struggling with Ensure and soup to eating a McDonald's cheeseburger (with lots of water, of course).