I'll be 48 in October.
MS has many different forms, mine is not expected to be aggressively degenerative. I have a friend who has a progressive form which means every event he has signals the arrival of something new that stays with him, numb left thumb last time, still there joining everything else that has failed... Mine is a chronic fatigue, wobbliness, weakness and pain, a bit like proper flu..it comes and goes completely until next time. I have 'events' or 'attacks' and they may last for 3 months or three days and then just go and you wouldn't know I have it.

As to dying 'early'..well, it's always too early isn't it?