I know one person on this forum has had fibromyalgia for 16 years, but I agree, it's new enough to have left a lot of doctors in the dark. Insurance claims and disability can be an uphill battle without a committed doctor in tow. Part of the problem is the diagnosis, like you've said, ruling other things out first, which takes time.
I hope you get the good news you're after; working a regular shift is all but impossible for me these days and I'm on disability leave, but that runs out soon and I'm not sure what to do.
Research is being done, I'm not sure what would cause this - drinking water, environment, stress, all of it's bad on a body.