this post shows you in what order the affixes go to do damage, from the BWD (Base Weapon Damage) up to +ED. the +ED is last before you start getting into other damage multipliers.
by the way, is this a Farming Build, Ascending Build, or a Hybrid Farm & Ascending Build? and are you climbing floors also?
to help out with your defense problem, take out all of your +5000 Poison and replace them with Epic +10% Dodge. this should give you +40% Dodge, with the +10% Dodge each Character starts with, and +10% Dodge if you have dexterity 20. this will give you a total of +60% Dodge (cap) plus the +15% Block on your OH. sure, you lose a little damage, but as long as you are alive, you are still doing damage to enemies until THEY are dead!
since you are getting 1 shot killed, the Armor on Spike is useless. change it to +20% Poison (make sure you use Calcite to change Spike to Poison Element). this will help make up for all the +5000 Poison you took off. also, for that Legend +200%ish Weapon Damage to be useful, make sure you have at least 50 or higher in Power Stat, plus what ever you need in Mana.
do you have Twister Skill on the Hammer? if not, change +10 Twister to +10 Storm to make Storm Proc more powerful or to another affix that is useful.
hope this helps.