Wow!, Soory to hear about all your issues. Generally no one really can say what would be causing your problems. It could be a number of reasons. Just stay in contact with your doctor and let them handle your symptoms. Withdrawals can vary. I have read some stories of people who say it is like a heroin withdrawal and any one looking to get off of it should step off slowly. In my opinion it scares me that you are taking vicodin (a highly addictive narcotic). Maybe your doctor needs to reasses your situation. I understand that fibro can be painfull, but vicodin?
Pat