I have just gone through six weeks of radiation w Erbutux (monoclonal antibody) for squamous cell cancer in my lower lip. It started in December and ended in January. I don't know that my experience will be that close to yours, but I will tell you that I managed to get through the process and of course there was a good deal of lip and mouth pain that has now almost finished.
I can't say anything about chemo. although I appreciate your analogy.
Hang in there. you'll get through this.