Fibromyalgia is a very common problem that does affect at least a few percent of the population. It is probably due to some central processing problem of pain signals which make them much more severe than what they are, leading to a chronic pain problem in those with fibromyalgia. A number of conditions are associated with Fibromyalgia such as a number of arthritis related conditions, but most cases are just the Fibromyalgia on it own. Fatigue and sleep disorders are commonly associated with it. There is also frequently pain in a number of specific trigger points in the body and the presence of these is part of the process of making the diagnosis. This is a miserable condition and people with it are always looking for the miracle cure.
Fibromyalgia does not directly affect the foot, except for the trigger points, but those with it will experience significantly more pain from a foot problem if the have one. this is a particularly the case for conditions like plantar heel pain and plantar fasciitis.