[TOMT] movie: woman goes crazy, dyes hair, sees demons.

Okay so, I'm looking for the name of a movie. I watched it somewhere in the 2000's I believe.

A woman moves into a new apartment with her husband/boyfriend. Slowly, she starts to go crazy. She dyes her hair brown (from blonde) and sees demons in the faces of her friends. She eventually ends up institutionalized, and I think breaks a glass door and cuts herself with glass shards.

I originally thought it was Charlize Theron and Keanu Reeves who starred, but I think I'm getting that confused with Sweet November and Constantine. Nothing on either of their IMDB pages is helping.