You are dying because no matter which class/build you play. Surviving depends much more on active skill usage( aoe blinds, CC, evading, blocking, dodging, boons and the list goes on.) to survive/mitigate damage than any other MMO out there. You cannot just stand there and "tank" the damage. No one can no matter how tanky they are.
My suggestion is maybe trying to look up some info videos about how combat mechanics work in GW2. And maybe look at Metabattle. They have some pretty decent builds for every game mode, and usually explain how the rotation/gameplay works etc.
Best of luck with this game, and I really hope that you at some point will come to love the combat as much as I do. Since it is the best in the industry, but yeah the skill ceiling is also the highest. 🙂