I agree with Ball, you're gonna have to spend a LOT of time killing things. Drop some vit for De, top facetanking and learn to kite properly.
The Vitality is needed to stop dropping like a friggin brick FROM RANGE. Find a Jailer/Vortex/Fast/Mortar and im toast.
And yes i had much higher damage before i changed my entire set of gear for Vitality stacking. Why did i do this? Because whilst i was really good at killing things, if things ever got close to me they could knock me on my !@# faster than you could say smokescreen. (oh and i am using smokescreen AND gloom constantly despite constantly using slows and running running running)
I was talking 1 hit death here, not 2 or 3 or even 4 hits. 1 single hit and dead by champions or elites in Act 1 Hell.
And you know what, im STILL dropping like a brick. Just takes 3-4 hits instead of just 1. So all things considered, im doing a hell of a lot better with much lower damage and 3 times as much health.
So far, ive managed to get the majority of my gear with higher Vitality than Dexterity, with all slots (except weapons as they have rubies) filled with amethysts.