Financial demand from Mother in law and mental torture

I am a Hindu married in 2014. It was an arranged marriage. I am a working woman, when I got married I was working and am continuing even now. My mother in law was staying with my husband at the time of marriage. After marriage I came to know she is unofficially separated from my father in law due to strained relationship between them. This fact was not disclosed at the time of marriage. I share household expenses and home EMI with my husband as per our understanding. We have no issues on financial front. I also do all household chores single highhandedly. However, my mother-in-law has this constant demand that my husband should not pay any of the household expenses, all bills, her expenses, travelling for family functions and gifts should be paid by me. I told her its personal matter between husband and wife and my salary is limited, then she gets extremely angry and starts yelling. In the past she has asked cash from me also which I had obliged. In the past 2.5 years since our marriage she keeps bad mouthing about my parents constantly as they didn't meet her expectations during marriage function. She has extreme anger issues and takes a violent form when angry. Its emotionally and physically draining for me. She is also not ready to go back and stay with my father in law at any cost. I have snapped all ties with her. My husband is supportive of me and defends me when required. But he can't repeatedly tell her to go back as she is his mother. I and husband cannot shift anywhere as then she will have to remain alone. What should I do? Can i take a legal recourse against the mental torture and constant financial demand? What evidence is needed as most of these have been verbal?