Hi! You know, to give you the best answer, I think I should ask you a few questions first that will help define the problem and the situation.
Is your question what is her mental health problem?
Or: Is your question what can you do to make this more bearable for you?
If so, can you ask for a different partner?
If it is what is her problem, were there these kind of traumas in her her childhood? What about alcohol or dysfunction in her family when she was growing up?
Is she getting any mental health treatment right now or in the past? If so, for what and what type? How is it going?
Any extra information that will help, feel free to share.