Hi Scifigal, and welcome to this branch of the Family. :)
I'm glad you will be speaking w/ your rheumy soon re your back & possible FMS. S/he is the person to see!!
I have OA and a very messed up back, also. I have tried some 'Fibro meds' in the past, they really didn't help - mostly caused some new problems. I do take a muscle relaxant and that helps considerably. For most of my FMS pain I rely on Advil. For my OA pain, I do have pain meds - but I hate to use it. My rheumy wants me to take it on reg basis, but I wait until I hurt so bad I could 'kill sumthin'. lol
My left leg goes numb on me when I'm in bed. I sleep on my side, so I try to sleep w/ a small pillow between my legs. It helps to keep them level so the nerves aren't pulled. Also, before I get out of bed, I stretch my feet and legs for a few minutes. It does help w/ the stiffness. I continue to stretch all of my body during the day, so it helps against the stiffness & exhaustion.
I found the FMS list yrs ago, what a revelation! I had about everything, except the 'guy' stuff. ;)
I wish you the best w/ all you have going on. Let us know what you hear from your rheumy.
God bless. Alice.