Hello Confused,
There are several here on disability of one type or another. I am just returning to work after 4-5 months of disability insurance claims. It seems to be different for every insurance company - and different for Social Security Disability.
I had to wait a couple of times for the insurance to review the claim when there was new information from any medical testing.
If you do a Google search for Fibromyalgia Disability you will find some recomendations that I found usefull, #1 of which "They don't care what diseases you have, they only care how they are affecting you and what proof of this there is."
I will shut up now and let some of the others give there advise.