Here is a site that talks about lots of different disorders that could be considered "MS mimics", or "what else it could be":
http://www.msfocus.org/publication_articleDetails.php?id=15
While certainly a diagnosis of MS is scary, it is not as bad as many other illnesses one could be diagnosed with, and these days, at least, there are some treatments for MS that are helpful. Many of us have lived and continue to live with MS, for years and years.
Come back and let us know how your testing goes.