Hi Lorie,
I'm glad the Carnation Instant Breakfast is working for you. I liked the espresso flavor - for some reason I never lost the "coffee" taste bud. Coffee milkshakes worked well also. It took time for my tongue to heal also. It and the back of my throat where I received the bulk of the radiation healed the slowest. It takes a lot of patience. And I too struggled for a long time with multiple issues. I had an ear ache for a long time due to the eustacian tubes being fried out and having to regenerate (causing a fluid buildup). I don't think that the swallowing issues are that unusual this early. I still have swallowing issues once and a while. I gagged on eggs for a while. Have him try experimenting with the size of the morsel and where its positioned in the throat on the tongue prior to swallowing. Also wait until the really heavy post sleep gunk clears before attempting eating. Moist is good, butter, olive oil and mayonaise are great lubricants. I also always used a straw when drinking liquids.

The post nasal drip and thick saliva just stopped one day. The gave a decongestant and it helped a little - but it will dry you out though so it's a trade-off. I found myself just taking one before bed. A humidifier is a good thing to have also - I still use mine.

It's very easy (and normal) to be discouraged at this point - you may want to ask your doctor about anti-depressants.