Hi, I can understand the distress you are through. Her complaints are suggestive of mood disorder. Although I need to examine her symptoms in more details, but her problem is indicative of a condition called Bipolar Disorder. It is a condition where the mood swing in between two extremes. There are cyclic phases of extreme anger, aggressive behavior, talkativeness, etc and at times depressing phases. It is treatable.
Next Steps
I would suggest you to consult with a psychiatrist. For advice on treatment and management, you can also consult with me directly here on practo.