The build i'm following feels squishy

Hi

I'm curently following the Toxic Rain Champion build from POE Beginners website. I'm level 84 and currently running lvl10 maps. My dammage is okay enough but i feel really squishy. Some bosses and elites take almost all my HP with 1 or 2 hits. My res are well above 75, chaos res is at 55, almost 4k life. Can you please look at my build and suggest what i should do to have better defense?
Thanks