What Elindor said.
Basically use your head...
If you have low ironflesh/strength, low tier gear, and are moving into the enemies swing, and get hit in the head hitbox, you're going to take a lot of damage.
At level 34, I have 21 str and 5 IF, wear a 45'ish armor helmet and I still get 1 shot sometimes by people with a lot of power strike.
There's level 33, 34, and 35 characters who literally put all their attribute points into strength, and convert skills to attributes to give them even more. Some of these people have literally twice the power strike/strength that you or I do. It hurts when they hit me. Also the game has a lot of random factors involved that can drastically increase or decrease damage without you doing anything differently.
you start a lot of rage threads if I recall correctly. I'd suggest finding a group of people (a faction) who's been playing the game for a couple years and play with them. it doesn't seem like these threads you start are really looking for advice, more that you just want to complain about something.