Debra,
Welcome -- I'm glad you found this site. I know this phase of treatment can seem really tough, but as Danny said, you shouldn't assume that the way your husband feels now is a permanent condition.
I was 39 and a non-smoker when I was diagnosed 17 years ago, and had surgery followed by conventional radiation, as IMRT wasn't around then. While I went for quite some time waiting to get my taste buds back (and dealing with dry mouth issues), things have improved substantially over time. Much of my salivary flow has come back, my taste buds completely returned, and I enjoy cooking (and eating!) as much as ever.
Just try to take this one day at a time and don't let yourself worry about what's way down the road. Be sure he's continuing to get the daily nutrition and hydration he needs, as well as pain management, to help him recover as quickly as possible.
Cathy