Yes as I would guess most of us were, I was also horrified when I heard those two letters.
I was terrified that I would be bedridden by the end of the month. Truth is, and I know I'm lucky and not everyone is this lucky, after 10 years I'm still able to work like a dog and run a 10 minute mile. Not too impressive but at nearly 50yo with MS not too shabby either.
The best advice I can offer is to hope for the best but prepare for the worst. Make plans now that will serve you well later if needed. Best to you.