@Nichelle I tried to read Campbell (what with being a Star Wars fan in the '90s, it was kind of the done thing) and failed, I'm afraid - the prose (at least in IT translation) was just unbearable.
I have read & enjoyed Hamilton's Mythology around the time when my children were born so memories are hazy, but I *think* I remember her being very judgy about the darkest parts of the mythology (and related cults), which I can understand but detracts from the "folk horror" part of my search =)