One-shots / stagger

I played through the game a few times now, and there's still one thing I don't get. At all. I'm in a base game right now, so no NG. As the title says, one-shots and according staggers. Currently I have 3.000 HP. From a lot of different elite enemies, some attacks deal 2.500+ damage. Which already seems quite excessive. One hit for multiple heals? (Especially with incredibly slow, clunky ones) But the worse part, is how every attack of an enemy takes you out of the fight forever. The amount you get staggered. And if there's multiple enemies, there's a very good chance getting hit once will kill you. No chance to get out. Mashing the dodge button as if my life depended on it. But there's simple too many perfectly aligned enemy hits, that re-stun you. Resulting in, technically, many one-shots. Similar with bosses, where I rarely ever get hit once. Usually get hit by the whole combo, just staring at myself getting whooped while staggered the full duration. I know there's some ways to reduce stagger, but I found nothing so far making a real difference. Is this just how it is? And I'll have to accept this is how the game plays? Or is there something to directly improve this?