My first thought...go to a new doctor. I have a very good friend whom is very depressed and needs something for the depression, yet our PCP doesn't feel he's in need of meds. Of course, when my friend goes to the doc, he laughs and jokes with him about
guitar's and knives and doesn't let his true self show...that's his mistake, not the doctor's.
Your husband may benefit from seeing someone else...they will at least run some tests. I know it's difficult when you know something is going on and the doctor disappoints you. It has happened many times to me. I think I have had fibro for 20 if not 30 yrs and I was diangosed in March.
Don't give up.