I remember watching someone struggle with that fight for a long time, so when I finally got the game I tried it once, got my ass beat, and then decided I would go do whatever else the game would let me until I felt ready to kill that boss. Several hours of aimless exploring, boss fighting, and stumbling into way over-leveled areas (you think the catacombs suck normally?), I finally went back and took on the boss. I had gotten a halbred (still my favorite weapon, halbred4life) and leveled the fuck out of my strength, vitality, and endurance. I had decided that real men didn't use shields, and wielded my weapon with both hands. I also faced battle butt naked, save for a giant helmet in the shape of a boar's head.
I swear it couldn't have taken more than 10 hits to kill them both. The first was dead before the second had made it half way across the roof. My only regret is that nobody saw it.
Moral of the story; if at first you don't succeed, grind until you're hilariously OP and beat the snot out of them.
Dark souls will let you go to a lot of places before you have any need to, so if you're ever feeling stuck, you can just go fuck off for a few hours in some other place and kill one of the numerous non-essential bosses, mini-bosses, and jesus-christ-what-do-you-mean-that-wasn't-a-fucking-bosses. Travel light, don't accumulate too many souls/humanity, and explore the game.
I killed Havel and a bunch of dark knights by flinging poo at them. And pushed Patches off a cliff. The possibilities are endless.
