Feeling squishy - cws chieftain update (still feeling squishy)

I've followed everyone's suggestions and managed to farm my way to a real nice rolled defiance of destiny ect and even at that I still feel way squishier than I think I should, I've tried to copy emmericals Pob as close as possible and don't get me wrong my gear isn't gg or anything but my ehp is showing 18k while his shows 40k+ I feel like I must be doing something wrong to have that big of a gap with simmilar enough gear

My POB: https://pobb.in/ThHPvizFqm4m

His POB: https://pobb.in/C48z-w1IHbOF