It sounds like you're getting it from all angles. Is there any chance you can get to see another doctor coz as soon as you see one that understands fm you'll get the right help.
I spent years like you, i refused to believe i had it, i couldn't say i had it and what i eventualyy realised was i didn't think it exsisted.
But whtt does exist is all the pain and torture that goes with having it. So whether you or your doctor thinks its fm or something else the main thing is that you get help.
you cannot go thru the rest of your life like this, so perhaps this is your first step in acknowleging you have it.
Acceptance from yourself is the first thing you need.
Above all, change doctors..........i had four different ones, now that i know it's fm, i stay away from doctors and rely solely on my own treatments.
take care and i hope you get help, as a basic human right you deserve it.