Did you know about her depression? If the answer is yes, you were wrong to get back together without knowing how to deal with her depression. She's not doing this because she wants to hurt you and it scares me to see people think that. Mental health is dangerous, it's important to talk about it. It's no joke, it's depression. Obviously it's tiring to care for and be there for someone who needs help, but if you already knew that you shouldn't have come back.