Diablo 1 HD Hellfire Mod | Awake

Hi, I've just built a barbarian and I'm liking a lot this class (at the moment). I'm encountering some difficulties on hell levels on nightmare, while I can easily take down monsters on hell levels on normal even on $player 10 (except seal bosses). I've just reached level 34. Should I moveto another area? Continue to ran hell levels? Which areas are best for leveling up my character? At which level should I enter hell levels on nightmare?

back when i played a barb i found using apocalypse to be pretty useful for farming nm or getting to hell bosses.

Stack mana items / farm for -enemy fire res items while retaining melee survivability. Spam apoc and teleport into melee range.

Personally i used an infereno sword and a unique shield (dragon something) as my apoc spam offhand, and whatever else as my main melee.

This was before the barb+warrior buff though. Make sure to make full use of insane, inner fire, sacrifice and other skills. Don't go ALL vit.

From what level I can find Apocalypse? Propably , It's impossible on normal , but where on nightmare - hell?