Boy, everyone is different when it comes to beds. I couldn't use the memory foam. I couldn't roll over at all. I was like that guy in the commercial that was "buried" in it! LOL
I have a pillow top mattress with a foam egg crate on top of it. I then added a fiber bed topper that I found at Bed, Bath and Beyond on top of that. A fiber bed is like a feather bed but you can wash it. This combination makes the bed as comfortable as I can make it and still have some support for my back. I still have a lot of pain and stiffness when I get up. That's part of the territory of having fibro. That most likely will not change.
I hope you do find what works best for you. I have gone through so many beds since fibro. When my husband was alive it absolutely drove him crazy. He would no sooner get used to a new king size bed and I would want to get rid of it. Finally, our last bed we bought two single extra long twin beds and pushed it together so it was like a king size bed. He was happy because if I wanted a new bed, I could get a new twin bed and he could keep his side. It was cheaper that way, too.
Sherrine