Level 52 Pal - underequipped and overwhelmed

Subject says it all. I'm in Nightmare, too high level to get much use out of Act 1 and 2, but any farther on and I get my but kicked. This is my first (well first after 5 years off) character, and I just don't have the gear to survive.
Should I be focusing on XP? I don't think I have the chops to solo NM meph, but if I go as part of a pickup group I'll probably never get the drops.
What should I be doing?|||

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Q u o t e:
What should I be doing?

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Tell us more about your paly, like what stats, skills and gear he has. This helps us aiding you.|||Level 52 Zealot, gear is mediocre.
311 def ancient armor
Naj's circlet
150 def royal shield (25ish resists?)
IK gloves
Infernal belt
25ish def rare boots with some minor resists
jewelry is some random rares with a collection of minor mods and resists
Weapon is a rare war javelin, 8-32 damage, 7% life steal, some minor electric damage, extra damage to demons.

I feel like I definitely need a better weapon, ideally better armor and jewelry as well, but I don't know where I should be trying to get it.|||You need a better weapon.
You should have collected some perfect gems and runes by now. If you take a socketed sword or axe, and you put 3 or 4 perfect topaz in it. (Or some ort & ral runes) then you should be doing a bit more damage.
try looking in the shop for a better weapon. Maybe you can buy a 200% ED sword or mace.
Try to make cheap runewords like Ancients pledge (ral ort tal), rhyme (shael eth),
for more -> http://classic.battle.net/diablo2exp/items/runewords-original.shtml
|||Once you hit nightmare, three things are almost (and I'd suggest even dropping the almost) necessary for a melee fighter. The first is life leech. Cathan's rings or a weapon with a perfect skull in it, providing the base damage is decent. The second is Cannot Be Frozen. You can get that from something like Hawkmail, Rhyme or the popular Raven Frost. The third isn't as crucial for nightmare, but once you hit hell, it will take you 10 minutes per opponent without it: Crushing Blow.
You can get it from things like The Gnasher or (the often overlooked) Guillaume's Face. You can also get it from a cheap runeword like Black or Strength. However, as Steuntron mentioned, you will want to keep a weapon some nice base damage. Perhaps the crusher in one, and your bruiser in the other.
If you can get a 3 socket paladin shield with +20 resistances, an Ancient's Pledge runeword will put the bonuses around +70, and you get mana back if you get hit.
Last, you may want to consider having a mercenary with "proper care and feeding" although I suspect you've already done this. Although the Act 2 mercenary tends to be the most popular, a rogue with a nasty bow or a barbarian with a decent sword can still make quite a difference.