I have no idea what that would be. To me, it does not sound like MS. MS symptoms very often respond to steroids. It doesn't make sense that you would get worse after steroids. Have you ever been tested for Lyme disease? You may want to post on that forum. They often say that steroids causes their symptoms to worsen.
Have you seen an ear nose and throat doctor? Teeth can hurt from sinus problems. You may want to rule that out. Toothache is not a typical sign of MS. http://www.mult-sclerosis.org/diagnosingms.html
Check out that website. It talks about the typical diagnostic process of MS. Best of luck to you. I hope you find relief soon.