My interpretation of this song is that it is about a woman in a relationship gone sour. Something happened in a past relationship which she is not proud of. By starting a new, innocent relationship she thought that it was all behind her and she could start anew, but her past came flying back (maybe she had an affair) leading to the destruction of her new relationship, leading to her hitting rock bottom. She's lost all of her friends, her relationship and she feels like it is all her fault and she has lost everything that mattered in her life.
My interpretation of this song is that it is about a woman in a relationship gone sour. Something happened in a past relationship which she is not proud of. By starting a new, innocent relationship she thought that it was all behind her and she could start anew, but her past came flying back (maybe she had an affair) leading to the destruction of her new relationship, leading to her hitting rock bottom. She's lost all of her friends, her relationship and she feels like it is all her fault and she has lost everything that mattered in her life.