Managing mana for blessed hammer without runewords on a low level paladin? Is it just potion spam?

So I'm playing Diablo 2 for the first time, and I made a Paladin, I got through normal with zeal + holy freeze but I started getting my ass handed to me at the very start of nightmare.

So I respeced and instead of zeal I put a bunch of points into blessed hammer. The damage is great but my mana is gone in all of like 2 seconds.

I put a point in redemption and started switching to that from holy freeze to help restore some of my mana and it does make a difference, but I'm still having to fill my entire inventory with mana pots and quaff them like crazy.

I'm trying to avoid runewords on this first playthrough unless I absolutely need them and can't progress any further in the game otherwise - so the usual trick of getting insight on a merc that I've read about isn't an option for me until I give up on that plan.

Will I be able to sustain the mana use with other gear? Or am I stuck with pots or maybe better off going back to zeal until I decide to allow myself runewords?