Help with EV/ES defenses

Hey, first time playing a EV/ES build since 0.1, got it into endgame. The issue is when I run like any t15 map, i get one-shot by pretty much anything that touches me... Playing a monk with quarterstaff currently since i need some lineage gem to get my planned build going and to switch to spear.
The problem I have is that I got decent(?) defense gear, and idk what I should do to stop getting killed by like everything.
Currently got 14k evasion, all res maxed and 2k ES. Also running Ghost Dance.

Gotta say that my Armor/ES character felt like 10 times tankier with worse gear, smh

Get one-shot by pretty much anything -- that's not what truly happens.
1st of all, you want to find out what one-shots you.

In many cases, if you rely on ES, it is likely chaos damage, assuming you have all the elemental res gapped 75. Because chaos damage deals 2x on ES. So if you have 1k hp + 2k ES, many things can one-shot you, even if you step on a chaos/poison ground, you will pretty much be killed in 0.5 sec.

I have the feeling in 0.4 the enemies are doing a lot more chaos damage than before, not sure if that's true. Earlier in the day I saw a giant starfish spews venom at me, that cleaned my 5.5K ES - that will definitely one-shot many hp-armour based builds (they literally have no option against chaos) and low ES builds (like 2K ES in your case).

In some other cases, it can be physical damage, if you don't move around when a big guy smashes a tree or something like that on your face.

So in general, you would want make the ES > 3.5K (especially in 0.4!), and keep moving around (physical is less of a problem when you have >3.5K ES). Try to get some chaos res, it is not easy but having 20% will help a little. As an example if you have 1.5K HP and 3.5K ES, getting hit by a 2500 chaos damage will leave you ~700 hp. If you have 20% chaos res, you will end up with 1200 hp.

Chaos Inoculation (CI) can be another good option in many cases.

Evasion does good job at the small projectiles, like those little sea ​​urchins. But overall, don't expect it will help a lot when it doesn't work together with deflection. Also keep in mind many damage in the game are designed to be unevadable (I am pretty sure there is an `unevadable` kind of tag in a good part of attacks/spells), so in those cases evasion contributes 0 to your defence.

Overall, the defencing system in POE2 is completely broken, so some classes are just bad options (warriors with 2.5K HP and 0 ES for example always get one shot by a 2.5K chaos damage and there is nothing they can do). Monk is however OK AFAIK. It is a lot easier to get a good amount of ES than HP.

Not sure what level you are, but if you're around level 80, it shouldn't be too hard to have something like 5k or more of combined ES and life.

It will affect your evasion of course, but you should still be able to get like 4k es+life if you wish to keep +10k of ev.

Wind Dancer might be mildly better than Ghost Dance at the moment, tho you can have both really as they are both 30 spirit. What you wanna do is to slot Blind, Maim and Magnified Area supports on the Wind Dancer.

Dont forget also to pick some nodes for stun and elemental ailment treshold.
I always take "Abasement" and "Shimmering visage" on my monk + try to get stun treshold on your gear, i use the heavy belt.