I don't know what to improve on my build

It's my first time reaching the end game and doing maps, i think my main problem is that I'm not killing, some mobs and bosses just don't die.

https://pobb.in/WQ8NsbBk4NIK

You are stun immune but for the life of me i can't find any crit avoidance.
No immunity against corrupted blood neither having a flask for it means your end up dead most likely unless you can heal yourself with very fast reflexes something i can't do for sure. But perhaps you use spare parts armor against those bosses. If your not swapping it in with either an empty socket jewel or other piece of gear against those bosses your being setup for failure. A big crit in the higher tier maps also can easely overwhelm your health as you have no block.
Your rings don't have blight enchants to help you in tower defense.
Your amulet doesn't have any blight skill allocated to it! I would recommend do this first it's a HUGE help just look up list of annointments.
Your armor isn't enchanted extra with exotic currency (*lesser/greater/grand eldritch ember and ichor prefixes that can give extra bonuses at random)
You don't have any gear with an extra mod on it crafted, you will need some for the high/tier uber bosses but those are expensive like 10 div upwards. (Can craft multiple mods combine it with ilvl 86+ and you will see it can have some unique mods. Your dps is just low at moment but with that annointment on your armor and lesser eldritch prefix on your head gloves and boots you can already find at tier I maps and aren't expensive to buy either. Then lookup high ilvl gear and see if you can find better then you currently have.

I hope some tips will help you to move a bit forward. Ofcource best advice is to sit down a bit into and get into crafting, and read resources about all the afflixions you can receive and how to protect yourself from it. Even if you don't craft yourself in the end it teaches you about level of gear what enchant they can have from what item level and chooce the best ones to look for on the market in your budgetrange.

In my masteries I have
'You take 30% reduced Extra Damage from Critical Strikes'
And
'Corrupted Blood cannot be inflicted on you'
And my life flask has immunity to bleeding.
The problem with my amulet is that I need it to have enough attribute points in it, if I take it off everything falls apart.

Is there any other passive to reduce critical damage?