Hello Barry and welcome ,
My husband had stage 4 Base of tongue . You are right the treatment is horrendous, but absolutely worth it!
He is now back to his normal, annoying, old self, and I have no hesitation in giving him as hard a time as he deserves!
Just kidding, but I know how you feel..... scared silly.
There is a light at the end of this rotten old tunnel and we can help you through it.
Take Care
Marica