Eric, I'm sorry you are dealing with this, too. Many of us have several other illnesses to deal with besides fibromyalgia.
I don't believe there is any connection to fibro. Ankylosing Spondylitis is an inflammatory illness...in the arthritis catagory. Fibromyalgia isn't an inflammatory illness, according to the doctors.
My brother-in-law developed this illness many years ago. He was a golf pro at the time and had to change careers. But, he did what the doctors told him to do and he followed through with the exercises, and he is doing great and plays a lot of golf, too! You wouldn't know he even had the problem. So, do what the doctors tell you to and this might not be as distressing for you as you think it is. I hope this all gets better for you.
Sherrine