May I suggest that if you haven't already, you visit a doctor other than your podiatrist. Your general practitioner may refer you -- I would think to a rheumatologist and/or an orthopedic surgeon specializing in lower extremities, maybe after that a neurologist. If indeed you have fibromyalgia, you should have more than a podiatrist on the case. Even more than a GP.
Numbness (and tingling too) is a symptom of tarsal tunnel syndrome (just like they are symptoms of carpal tunnel syndrome when you have them in your hands). Has anyone suggested doing an MRI to look at the soft tissue in your feet? At any rate, as helpful and informative as this board is, I think you need professional attention and expertise to get a correct diagnosis before proceeding with a lot more treatment. From your post, it doesn't sound like you have a correct diagnosis yet. I would go that route first, then find appropriate support groups for information and ideas.