Michele, I'm not a doctor, so take this for what it's worth. But I thought zanaflex is a muscle relaxant to be taken occasionally for someone who's pulled a muscle. At least that's what my doctor told me. They told me to try it (when they thought I just had a pulled muscle in my back), and it didn't do diddly squat for me! The only thing it did for me is make me feel drunk (very dizzy and uncoordinated) the next day---and it gave me horrible constipation!
Also, I read that it's not to be taken by pregnant women because they're not sure if it will do harm to an unborn baby or not. If there's any chance you could conceive, that could be dangerous.
It sounds like this doctor doesn't know what to do with you, so he's grabbing for straws. If I were you, I'd get another opinion. You deserve to have someone who will give you the care you need.