phys reflect almost killing me having literally no phys dmg

hi,
i am running a volatile dead hierophant.
trigger skill is frenzy which brings me to a total of 140 pdps.
why is it that i almost oneshot myself in a phys reflect map, having 11k es ?
it is not versus any mob but some almost kill me. or the mortar effect most likely.
makes no sense to me.

edit: even with 48% phys mitigation and 9% phys to cold.

Unearth with max Frenzy charges is the prime suspect in my book.

unearth
Deals (13-540) to (19-810) Physical Damage

tyvm

Use a low level one instead. The corpse explosions will deal less damage, but your main damage comes from the balls.