I think a lot of the sleep issues related to Fibromyalgia (and related disorders) have to do with the inability to get enough good quality sleep at night to carry us through the day. There was a period when I would be unable to stay awake. It was frightening, especially because at the time, I was in a position where I had to do quite a bit of driving for my job.
I can recall several times when I was sitting at red lights when I felt compelled to shut my eyes just for a few seconds. It was as if I had no control over my body. It happened several times at the same exact light, and I was on a very regimented work schedule then, so perhaps it had to do with the number of hours I'd been working, inability to move around, since I was stuck on a road in traffic, and there was no where I could pull off to rest.
That's when I taught myself to crank up the radio and sing along, keep the windows open if there was a breeze, or crank up the air conditioning to full blast on as cold as I could get it, just to stay awake. I'm very thankful that I don't have to experience that these days, because even now, years later, I feel sick to my stomach when I think of how it could have ended.