Sorry bro, so much empathy and caring advice out here hey. A bit more:- if she hasn't always been like that, and its not menopause? or not on drugs?. the psycho conditions others have suggested are possibles but Borderline Personality Disorder is often bought on by abandonment at an early age and covers a range of chronic mental challenges.
If that scenaro is just surfacing due to say marriage/financial instabilities, nothing helps calm these random non-menstrual rages lasting 1 to 3 days. Staying calm yourself is essential. Beware:- attempts to abandon a relationship as suggested by others (if B.P.D) will exacerbate an already "stark raving insane psychotic episode" to an almost murderous level, especially during an episode and even an announced proposed abandonment can bring one on in 3 minutes.
Hope for you it doesnt get worse before it gets better but do seek professional psycho advice?
"Dammed if you do (leave) and dammed if you dont" was surely coined by the spouse of a BPD person.