Welcome to our very exclusive club! Just so you know, I have MS and Hashimoto's thyroiditis, as well as a couple of other fun auto-immune relations. Auto-immune diseases are related in a way, so there are quite a few people who have more than one diagnosis to deal with.
It's great that you can exercise, I still can't do more than a few minutes at a time, so you are ahead of the game on that. As for the fatigue, Gretchen had great advice. I have been on Provigil since my diagnosis in February and I don't know how I survived without it before. Also keep in mind that you may need to continue to adjust your schedule. MS is a lot more serious than thyroiditis, and does require some lifestyle changes.
If you are diagnosed with relapsing-remitting MS your doctor will probably want to start you on therapy to slow the progression of the disease. The ones I can remember are Copaxone, Avonex, and Rebif. You can find out a lot on those by googling them. I think these treatments are only for relapsing-remitting, so if you have a different type you will have to look at other options.