Feeling squishy as Ancestral Commander MSoZ

Here is my PoB: https://pobb.in/33SoM3uGRRWo

After seeing the guide on here (https://www.reddit.com/r/PathOfExileBuilds/comments/1j57ouk/getting\_started\_with\_conners\_zenith\_ancestral/) and watching Conner's video I decided to give this build a try because I wanted something really tanky that doesn't get randomly one-shot in T17s.

I threw together the build with MB + Progenesis + ~100div investment in a short amount of time so there some things that are not yet properly optimized, like gems levels, missing jewels, leveling up to get more charges, etc. But I wanted to see what the build feels like before putting in more currency.

I'm generally happy with the damage at this investment, but I was expecting the build to feel much tankier at this point. I'm kind of disappointed because it's the opposite of what I expected. I'm constantly getting randomly one-shot in T17s, and sometimes even in 8-mod T16s. It feels squishier than my Blind Prophet LS build, which I thought should be inherently more squishy.

I know I need to fix my chaos res (EDIT: re-crafted ring to fix), but progenesis is always up in juiced mapping, but i don't think that's the only reason for constantly getting one-shot. Or is it?

Is there anything in my PoB that's just totally wrong? Am I overlooking something that should make this build tanky? Do I just need more life and regen (I swapped out the regen flask for MB)?

EDIT I just re-crafted my ring to cap my chaos res and get a bit more life. PoB above updated. But I didn't feel any difference in mapping, still super squishy.