Sozac said:
Also, no and I heard that this helps in the fight, but I can't go back so poo for me.
Why can't you go back? Its kind of a long walk, but there is absolutely nothing stopping you from walking the way back to Sen's Fortress. There is only one place I know of in the game that you cannot leave once you've entered until you've cleared it (Painted World of Ariamis).
If you can get some humanity, summon Solaire. His summon marker is on the stairs near the archer knight. Also, summon another player or two. Orstein and Smough is a tough part for anyone, so their are bound to be people looking for help, or offering to help (you can usually tell the difference by looking at their gear.) If you need some humanity, you can always invade Lortrec's world and kill him for it (provided you rescued him in the Undead Parish and you got the Black Eye Orb in Firelink Shrine).
Otherwise, take some time and just grind the monsters around the area. Nothing in Anor Londo is really THAT much trouble, once you've figured out their patterns, and you can get 10,000+ souls a run just by clearing the area between the Solaire bonfire to the giant blacksmith. Do that a few times and level up, and have the blacksmith upgrade your stuff.
As for the actual fight, blocking is less useful in this fight than dodging, so equip lighter armor+Havel's ring, or whatever it is you can to decrease your burden to about 25% ideally. The two of them are tough, but they telegraph the hell out of their attacks so dodging shouldn't be too much of a problem. The trick, like you keep saying, is separating Ornstien. If Solaire/another player is with you, just let them aggro Smough while you kill Ornstien. Otherwise, I'd recommend just moving A LOT. Stay close to O, but never stop sidestepping. And if you hear Smough start making loud noises, just back away and see what he does. I won't sugarcoat it, this fight will likely take you a long time without help, even if you play it perfectly. Its a marathon for sure, and it doesn't necessarily get any easier once one of them dies.