Does my wife have Factitious Disorder?

This is more common than you think. Many people crave attention and one of the ways they get it is through feigning illnesses. Changing doctors suggests she's not getting the answers she wants, but it's also a symptom of the illness you're questioning. What have the doctors told you? If she's not been evaluated by a competent psychiatrist, perhaps that would help. You obviously are experiencing some feelings of guilt, but you should be wary about feeling too much guilt about this - there is nothing you've done to cause what your mate it doing. Maybe some therapy for both of you would be helpful as well. Good Luck.