practice is everything.

Like Aevra said: staggered tremors to counter fear. ALWAYS drop your 5 grounding totems when they're off cooldown and you don't got 5 up.

And i don't know what level you're at, but there's a good chance any twinked melee class will rip you to bits. Try to ignore that, it'll happen to anyone. Since it's very hard to outheal dmg that killing you in 1 second. Play defensive and don't cast spell to pressure someone or to get dmg out. Cast spells to kill. Pick a target that WILL die. And be sure to keep yourself alive. Casting 3 Chain heals, then 1 CL + LB to kill someone and 3 Chain heals again can be needed if you got several enemy players swarming you. Or even just cast 5x frost shock on every CD. 2 shocks x5 should kill people if 1x 5 isn't enough allready.

Use Iinteract With Target to make your shaman face a melee that's dancing around you.