With your D level so low and stoppage of your Zoloft, I would say it is likely a combination of both. You are quite correct that it will take a little time to notice if your problems have been resolved. If your problems continue, however, do let us know, but more importantly, let your doctor know. At that time an MS Specialist might be the right direction to go. For now, relax and breathe deep. You are making the right moves.