Guild Wars 2

Ofc, you do something wrong. However you gave no info about your build etc, so no one can really help you.

Mesmer is all about active defense. Shatter F3, shatter F4, stealth, sword #2, blink, lot’s of dodges with vigor and such.
We do have plenty ways to not get caught. But once caught, yeah, we are screwed. Is how the class is supposed to be.