Help me fix my build: Storm Call shock

Hi all, I am trying to improve my old build for 3.0, and am not having much luck. Currently, I'm lv 90, but I'm stuck around Tier 11 (or so) maps, due to the total lack of survivability.

The idea behind the build is to keep enemies Shocked/Frozen/Chilled as much as possible, and take passive nodes that increase the effects of Shock, for extra damage.

Key Uniques:

Choir of the Storm: massive DPS boost with its crit chance and free lightning bolt.
Call of the Brotherhood: Converts Lightning to Cold so you can double up on some passive nodes.
Cloak of Defiance: Main source of defence with MoM.
Voidbringer: More crit, important for applying Shock and proccing Choir of the Storm.
Rathpith Globe: Defence.
Doryani's Invitation (Lightning): Leech and DPS.

Ascendancy:

Elementalist: Liege of the Primordial, Shaper of Desolation, Pendulum of Destruction, Paragon of Calamity. Basically the standard DPS setup, AFAIK.

Gems:
Primary attack: Storm Call, Less Duration, Spell Echo, Innervate, Lightning Penetration. Sadly, I can't afford a 6L Cloak of Defiance.

Secondary Attack: Ball Lightning, Spell Echo, Faster Casting, Slower Projectiles. Works well against bosses who don't chase you too much. The idea is to fire-and-forget Ball Lightning then keep Storm Calling them.

Mana Reservation: Herald of Ice, Herald of Thunder, Enlighten. Pretty standard.

Golems: Ice Golem, Lightning Golem.

CwdT: Immortal Call, Frost Wall, Tempest Shield. Some people really hate Frost Wall, but it's great for keeping melee enemies off of you.

Curse/Utility: Orb of Storms, Conductivity, Arcane Surge. Use these as an opener before spamming Storm Call.

Jewels: Lightning damage, Crit Chance, Life. Nothing special.

Passive Tree: https://www.pathofexile.com/passive-skill-tree/AAAABAMCAASzBUIHHgj0DkgQWBEPES0RLxFQEZYTNRa_F6Qb8RzcHYMi9CaVKgsrCiycLX0wWzLROlg7DTwFQZZFR0WdRtdJT0lRTLNTUlVLVcZXK13yXyph4mSdZlRo8mpDa3psC20ZcFJxhXIPdFV2EXyDfll-r37Hf8aCm4UyhXuJ04w2jRmPGo_6kPqTJ5RvlS6XLZo7muCdrp7En9-hL6IApr6nCKcrrJesmK6zr5uxQrWFvKq86r2CvorAZsG0yL_QH9D11AfVptlf2rncjd2M323fit-w4BLli-kC6-7r9ew47TzvUO987-vwH_DV8h3zEf6z?accountName=Metabug&characterName=Brightglimmer

As I said, the DPS for the build is decent, but I tend to die in one hit, especially to physical damage. Any advice ? One thing I'd love to do is get a 6L Cloak of Defiance so I can add Life Leech to my Storm Call, but as I said, I can't afford one yet; additionally, it won't really solve the "die in one hit" issue. I could also spec out of some DPS to take more of those much-needed Life nodes, but I'm not sure if I can afford the DPS loss...

Bump ?