Rolanda,
I know exactly how you feel. My mom also battled about 10 years of luekeplakia and then it turned to SCC of the tongue. She is now almost 8 months post radiation (when she was first diagnosed her ENT only did surgery it wasn't until her recurrance (or so called recurrance) that she received chemo & radiation). My mom after 4 months was also experiencing a lot of pain. We went on a week vacation in August and I could not understand how and why she was in so much pain. Extreme pain where it hurt her to eat and it even disturbed her sleep. She did not have blisters or sores in her mouth but what she did have is dead bone (it does have a techincal term). She went to her ENT when we got back from vacation and he noticed that her bone was exposed and he was about to do another surgery and biopsy but she made a visit to her dentist who noticed she had an infection and he suggested shaving down the bone. After a course of some very strong antibiotics he shaved down the bone and she started to heal quickly. Now she only experiences a small amount of pain and just takes baby aspirin for it. What a relief.
I would definately have your husband see some new Dr's who can help him. I couldn't handle watching my mom in so much pain. We were driving home from vacation and she said if she has to live like this with the horrible pain that she didn't want to live.....but now I can happily say that she eats pretty normal but she has yet to gain back a single pound. Things do get better but it really sounds like he needs somebody to take a look at him that can help him and figure out what is going on...
Take care,
Dani