you need to set a end game goal for yourself. there is plenty to do past main story, better gear, pvp, achievements and titles to get, more skill points, level other skill trees, adventure zone coming, join some guilds with different purposes, become the wealthiest adventurer, ect.

you really just need to find what you love to do, and personally i find main stories in mmo's a little pointless.

in my opinion this game did kind of make alts obsolete, if you think of each vr rank as 10 levels you do 50 in your faction 50 in your next faction and final 50 in last or 1-50, vr 1-5, vr 5-10. with alts your just going to repeat every quest. only purpose for alts is other classes.