Looking forward to playing the remaster at some point too...just may wait til it's on sale in a few months though. Everyone's saying good things about the remaster's quality so that's great.
Irithyll wasn't too bad, but definitely has a few stretches that are treacherous. What kind of build are you playing?
I have a few builds but the one I got the furthest in (to Irithyll) is a dex sword & shield build. I have an "easy mode" pyromancer build that I play on when I just want to have fun and not cry, but only made it to the Cathedral of the Deep with that one.