Hi, John.
You'll get your voice back, probably starting about a month out of treatment. I'm 7 months out right now and speak with a little blues singer rasp, but much better than I was. About the same time your voice comes back, you'll start to feel better and your mucousitis will be stopping.
Go back and read some of the posts here about how people cope with the various side effects of chemo/rad/surgery. There is a lot of knowledge here you wont get from the doctors.
Anything you want to know, just ask, the people on here should have all the answers you need.
Best Wishes, Mike