What's the Name of That Book??? discussion

This book was loaned to me a friend about 15 years ago.

Spoiler's Ahead:
From what I can remember the protagonist was a female and she was in the library, but I believe she was working in the library behind the counter and when the placed closed she found a note telling her to go somewhere, I believe this led her to the bookshelf which was where another note was that led her to a park statue that had another note and I believe $100. It also gave her another task, she wasn't sure if she should because it was beginning to feel creepy, but she did continue.

From then on things got really weird, and unrealistic, she was followed and watched but not sure if it was human or inhuman. Eventually, she ended up in a home with other women that were not fed and were eating themselves. She somehow escaped after days there by I think starting a fire.

She ended up fighting this non human entitiy in a church and then walking down a dirt road carrying it's head by the hair.

I know sounds aweful, and it was, but it was also a trainwreck that I could not stop reading.

The beginning in the library I'm pretty sure is In The Dark by Richard Laymon. The book is definitely listed on Goodreads but the add book/author link refuses to find it.

I don't remember the specific weird/gross details you give, but the book definitely got both weird and gross. That was kind of Laymon's trademark, and he was very good at it.

In the Dark for the link.

OMG, that is it!!! That is totally it! Thank you so much, how did you know?