Is there any way to know, at the age of 23, if ill die sooner from my ms?

Usually not issue: Although some prior studies revealed a possible 9 year shortening of lifespan, it is now known that use of disease modifying agents results in normal lifespan. So, at your age, probably best to use a potent dmt, and maintain treatment indefinitely. The great news involves current valuable drugs and even more effective ones on the way.