I'm dying without damage

Guys, tell me if I collected something wrong?

The entire build works on a single flask https://www.poewiki.net/wiki/Coruscating_Elixir
I see in the screenshot you provided, it has no quality and no enchant.
You have no mana, thanks to blood magic from the helmet.
Thus, your ivory tower means all damage bypasses energy shield.
And given your life reservation, having a small life pool would mean anything would hit you.
Without that flask active, all damage targets your life pool directly, which is why you would fall over the second your flask is inactive.

Also be mindful, with a low life pool you are weak to culling strike, so no matter if the flask is active, you walk around on less then 30% life, culling strike will kill you ded.

and how can I make it so that the damage doesn’t bypass my shield?

Can you link the build you have been working off to create this?

I can see you have made your profile public, which is very helpful, but it is also helpful to see the version of the build that is working. Information being passed on is correct, but it seems like there is a lot of mechanics to this build, and if one is off, it may not function.

Chaos damage is the only damage that bypass energy shield by default. Ivory tower makes chaos damage go to mana before life, but since you have blood magic, no mana means in effect it still goes straight to life. The coruscating elixir makes the chaos damage not bypass your energy shield, but only when the flask is in use. So if the flask drops off, you are vulnerable to chaos damage. Often similar builds to this will have the flask enchant reuse at end of flask use.

You have some life, so you might not die instant to chaos damage when the flask is down, but with the rapthpith globe, you are sacrificing life when ever spells are cast/triggered. So this might be getting low and you will die to even a very small amount of chaos. Even at full on 600, you can still get one shot by chaos damage if your flask is down though.

Not sure how you are dying out of combat. Are you fully dying, or just getting low on life because of the life sacrifice on spell cast? Can you explain this further. "just a shot and that's it". What does this mean? Are you getting hit by an enemy and dying instantly? Or are completely out of combat and dying when you use a skill?

One other thing on your POB. Your elemental resistance for fire and cold res looks to be capped by flask. So if you are not keeping them in use you could be taking a lot of damage from fire and cold. If you are dying through you energy shield, that might be contributing. Doesn't look like you have enchants on these flasks either.

Some information from the rathpith wiki:
"This modifier will not remove the user's last 1 life."
"For Low Life characters, the life sacrifice is negligible unless the player is purposely keeping their reserved life above 10% (to avoid Culling Strike...)."

So I'm dying because of the flasks? Well, I started from Atlas to pass and kill mobs, then, bang - one blow and I fell, I even keep mobs at the distance, I can't even understand that the long-rangers took me out with a kick blow... I realized that the skills are connected, but this one is correct with a good ratio of things or what?

Sounds pretty much like you are dying to chaos damage with flask down. I was looking at POB earlier and it said something like max chaos hit flask down 1400 up 14000. That's on full life if you going down below that you have no defense against chaos at all. Try running with all flask up and you'll know if the build is good or not. It's a major part of the build.

got it, thanks for the tip