Identifying an oldish B-movie

So there's a horror movie I saw between 2000-2010 that I've tried to find the name of, and I have not been successful.

I saw it on some kind of platform that I think was provided by our service provider, not cable, something like on demand. Sorry, it's been a long time.

Definitely a B-movie, not campy though actually pretty dark and serious.

The best details I can remember is that the antagonist was experiencing extreme delusions that were revealed near the end of the movie. The female protagonist's name was Rachel, which I remember because her name is repeated numerous times by a disembodied, hallucinatory voice around the climax as well.

The final detail is that near the very end there is a rough scene where the antagonist >!sexually assaults the protagonist. !< It was kind of in poor taste in my opinion.

Does anyone remember this movie?