Went back to my original DARK SOULS save and I have a lot of contempt for past me.
Basically, I left my NG+ character right at the bottom of Blighttown, at a time in the game before warping between bonfires is available. Trekked all the way up to the entrance to the Depths before I realised I didn't really want to go that way as it's the way I came down. When I tried to go back down to the swamp I was rushing and kept dying. Also, like a total casual, I built my first ever Souls character in a really inept way, with loads of DEX and INT and hardly any of the life-giving stats. No wonder I found it so difficult on my first playthrough.