Enh in pvp

[Piotrro]

Hey, any enhancement pvp player out there?
I am trying to play pvp in enh spec but... The shaman is always being focused. Literally every time I play bgs or arenas all enemies focus me at first, and I don't know how to avoid that damage. In all online guides ppl keep saying that "you dont need to do anything when the enemies are dead, just kill them with your epic dmg". But how am I supposed to do that? Any cc and I am dead. The enh is so squishy, the only one sustain ability is Astral Shift, and to be honest, comparing to other sustain abilitiest (of other classes), it is extremely weak : /

tl;dr
How to not die in pvp as an enh shaman?