need help. Necromancer character keep dying on T12+ map

Hi, can anyone help advise what is wrong with my gear/gems. Keep dying on T12+ maps. My resistance are all 75% or more.

My current gear set as follow:

For starters, where is all the life on your rare gear? You should have atleast 60-80+ life on all of your rare gear.

For summoner character, apart from life HP, does the armour or evasion rating, or any other attribute play a part for T12 and beyond maps?

Maybe I'm not getting something but your gems are all over the place. What is your main dps skill? For example Fortify and Main in your boots don't do literally anything. Elemental focus with your zombies does nothing, elemental army with your reaper doesn't make any sense either... I mean can you explain how your build works?

Was playing around with different gems set-up. have re-done my gem set-up and forgo my reaper. works better now with ability to clear T14+ maps without dying.