Well I just killed Queelag, took 4 tries. I basically avoided all her attacks until she stopped to vomit lava. Those butt blasts or whatever that one shot you were the most annoying. Blighttown/swamp wasn't that much of a problem, but I had those anti poison thingies from the forest. I didn't explore it too much though, that wooden construction is a fucking low fps maze. Now I'm gonna go kill that Butterfly boss, then maybe Sen's fortress, or should I try to kill that Hydra boss first?
Tbh the boss I had most troubles with so far was actually that Capra demon, I guess I have troubles fighting in small spaces and that room has so little space to dodge and move around and your camera is all fuked up. Until I figured that the boss doesn't reach me if I go up the stairs and the dogs will follow me, after that it was pretty easy.