Diablo Game Questions I have all the items needed for a Nat's build just not the optimal stats on it. How do people achieve 1M+ attack damage?

I have around 300k damage and 200+ which I know isn't much but I find it strange that a few stats would bump my damage six-fold. What are the most impactful changes I must do?

this is my character: http://ift.tt/2dOSF18

Thank you!