I, too, had terrible mouth sores, and thrush. I am now 2 1/2 months post Tx and can finally say it is tolerable. To keep things under control I still use what was prescribed for me called "magic mouthwash". It has antibiotics, a numbing agent, benedryl, etc. all wrapped into one and seems to help me a lot.
I am still on the peg tube and can't eat anything yet except cream of wheat, so your husband is probably still right on track.
Betty