--did you get copies of your test results that you can post to us, to give the amateur diagnosticians (who are very good, actually) some more to go on?

I am particularly interested in what your MRI's have to say--did they do brain and cervical, thoracic, and lumbar spine? Reason I ask is that given the presentation and timing of the symptoms you've related, my initial suspicion would be some form of central nervous system impingment or demyelinating disease. The problem, of curse, is that one can have the exact same symptoms from central nervous system disruptions as from peripheral nervous system disruptions; it's why one generally is in for a long round of testing to try to pinpoint the causes of neural symptoms.

I, too, have not seen a direct correlation between smoking and neural symptoms (though there's adequate correlation between smoking and a whole lot of other bodily dysfunction), But, if your symptoms worsen with smoking or drinking, there is an implication that there is a vascular/circulatory component to what's going on with you, and any survey should include tests for circulation as well as vasculitic autoimmune disease.