Can anyone help with this scene from a movie/series?? Stumped.

New to Tattle Life? Click "Order Thread by Most Liked Posts" button below to get an idea of what the site is about:
I watched a movie or a series recently. In it was a scene where there was a man who was mentally unwell. He met a girl and fell in love. There was a scene whereby she woke up in his bed and he was gone. She left the house and you see him in the attic talking to a voice he can hear in his head. It is either his mother or grandmother. it cuts to a scene where he is with his grandmother as a child and she is abusive. You hear him saying to her, no, don't take her away from me. You cant have her. He ends up trying to kill his girlfriend and sets fire to the house and I think he shoots himself with a shotgun. When the police arrives, they cannot find him. I cannot think of the movie or series this is from