I also just read the story.

IMHO it was misrated as R, should have been X, and should have had warnings for violence, rape, mutilation and attempted murder. The offending scenes were gross, horrible, sickening and probably triggering for those who've had similar happen to them.

It was fairly well written and out of curiosity I wanted to see how it would end. I just cranked up my suspension of disbelief and plowed thru it.