Your only options are to
Craft a new Drill
Steal it back
Make him give it back (He would if he's really your friend)
A Drill / Pickaxe is 100% necessary for progression in the game so if you can't do any of those for some odd reason you're out of luck.
No you don't have to make a new world, instead if you have 20 of all four pillar fragments still, you can create the Celestial Sigil at the Ancient Manipulator according to the Terraria wiki page. If you want to have the Lunitic Cultist to spawn again and you want to do Thebes's Lunar Events again, wait one in day game, or just exit your world and re join it....
As you'll be able to tell, I have fought this pillar a lot. Here's what I've found works:
Get full Spectre Armour with the hood for health regeneration. Full Beetle Armour works as well but you might have to retreat a few times during the fight to not die.
Build a platform just above the pillar (prehaps afterwards) and use Vampire Knives (healing) and the ...