This is not about courage or the lack of it. There is no way to battle and win against a mentally ill person. This woman is on her way to a bad end. Sooner or later the landlord will have to deal with her. Sooner or later something bad will happen in his building. Perhaps it will happen to him. Leave in an orderly manner by giving notice and leaving the place in good shape. Leaving on the best terms possible will enhance your chances of having your deposit returned. Please post again and let us know how you make out. Again, good luck.