I don't pretend to have a magic wand but, some of what you describe could be from Sleep Apnea and just accelerated due to his treatment. Please humor me.
Was your husband a snorer, light sleeper, tired most of the time or a person who woke many times during the night prior to treatment?
These are all signs and symptoms of sleep apnea and I have recently been involved with a patient, post throat surgery, who had similar complaints. After a sleep study he was diagnosed with severe obstructive sleep apnea. He has improved as a result of his treatment.
Just a thought.
Cheers,
Mike