Tressia,
Actually, my experience with a waterbed was not so great. I thought it would be, because I'd loved them before I got Fibro (at least, full-blown Fibro.) By the time we got ours, I was already having plenty of back problems. I hoped the waterbed would help, but the pain just got worse and worse. So, I don't really know how much was due to the waterbed and how much would have happened anyway.
But when we got a regular mattress about 15 years ago, it felt a whole lot better. Of course, I picked the mattress (my husband can sleep on anything,) slept on it a couple of nights, and had to ask them to exchange it for a different one! (The Princess and the Pea syndrome.)
Who knows, a waterbed mattress might be just what you need. Nothing's cut and dried with this crazy disorder. Hope you find what helps.