struggling at act 4 nightmare as a firewarlock

basically using this guide: https://maxroll.gg/d2/guides/fire-warlock-leveling-build-guide
i'm level 58 with the recommended gear, they shred through my merc or any mob that i bind.
apocalypse barely does anything

what am i doing wrong?
my gear is spirit,stealth,lore,ancients pldege,amulet + 2 to chaos skills and 10% fcr, goldwrap belt, magefist, rite of passge boots, generic rare rings with magic find and fcr%

the merc does'nt have anything good on him hwanin's justice bill, 212 def armor and hit recovery, crap crown with 44 defense