Guild Wars 2

Where do you mean? PvE, WvW or PvP?

pve mostly bosses in the harder dungeons

Dungeon bosses usually have a weak auto attack and one or more very damaging special attacks. Those special attacks will most often have discernible animations, create red circles, or both.
It important that you become able to read those tells and react accordingly; in most cases that means a dodge roll.

Greatsword #3 is an evade, so you can use it in addition to your dodges. Try equipping Signet of Stamina, and don’t active it; you’ll be able to dodge roll 50% more often, allowing you a greater margin of error.

Relevant: https://www.youtube.com/watch?v=IJODnlDOivc

If you’re dying with 22,000 hp you’d probably be dying with 30,000 too. You need to learn how to time your skills and maintain a good rotation. Know the boss’s attacks, be 1 step ahead of them instead of 1 step behind.

The way to be successful in a fight is to not be in the situation where you’re just reacting to an enemy. You won’t win like that. You want to get to the point where you’re in control of the fight and that will never happen until you get used to timing your dodges/whirlwind when you know the boss is going to attack.

Purple Miku.7032:

If you’re dying with 22,000 hp you’d probably be dying with 30,000 too. You need to learn how to time your skills and maintain a good rotation. Know the boss’s attacks, be 1 step ahead of them instead of 1 step behind.

The way to be successful in a fight is to not be in the situation where you’re just reacting to an enemy. You won’t win like that. You want to get to the point where you’re in control of the fight and that will never happen until you get used to timing your dodges/whirlwind when you know the boss is going to attack.

Sure: in solider gear with blood + water – you can survive 2-3 times more damage then regular zerker. But deal 2-3 times less damage.

You should try playing berserker elementalist 10k HP with light armor you are downed in 1-2 regular hits

Berserker warrior is the most forgiving class to play. Walk in the park. When stacking time your WWA and dodge the big hits learn the encounters it’s very important. When not stacking you should melee kite and time your 100b, WWA.