I can't imagine being held in suspense for five years. I had a tumor in my neck a couple of years ago, and underwent some serious radiation and chemotherapy, simultaneously.
"Head-and-neck" cancers are unlike others in several ways. Because there are so many different anatomical systems, and so many nerve endings, in that part of the body, treatment is more debilitating than most other cancer treatment regimes. The good news. on the other hand, is that you can be given an "all-clear" much sooner than in the case of other kinds of cancer. I only had to wait one year to be officiallly pronounced OK.
Again, good news, and good luck. "Yippie!!" indeed!