Antichrist (2009)

While a married couple (Willem Dafoe, Charlotte Gainsbourg) is having sex, their infant son in a nearby room falls out a window to his death. She becomes distraught and is hospitalized, but her husband, who is a psychiatrist, attempts to treat her. Deciding that she needs to face her fears, he takes her to a cabin in the woods where she spent a previous summer with the boy. Once they are there, she becomes more unhinged and starts perpetrating sexual violence on her husband and herself.