Mental Harassment

Hi, My parents have been involved in relationship issues with each other since I can remember. But in the past few years, the intensity and gravity of the issues has become immense. Since the past 6-8 years, we have seriously been doubting my mother's mental health. For no reason, she would suddenly pick a fight with my father and spoil the day and then would suddenly become alright and have normal conversations with us. This has been going on daily for the past few years and it has crossed limits. Due to her issues with herself and everything around her, our lives have become hell. There was a certain level of mental harrassment my brother suffered at the hands of my mother. He got married recently but soon problems started to arise and all was not well at home for the newly weds. The harrassment went to such an extent that my sister in law had to forcefully leave home and go back to her hometown in order to get a break from this hellish experience. Soon, both my brother and sister in law had to put an end to all this misery and thus shifted to another city and have been living there happily since 5 months. I blame my mother for the rupture in the family. Everybody in the house has reached new highs in the levels of insanity. I quit my job to be with my father and help him in his business and take care of home. But the harassment hasn't stopped, its just getting worse everyday. My mother has made my father's life miserable. He hardly attends to his friends as he has been insulted in front of them too. He has already been driven to two situations where he had decided to end his life. Recently, she called our business clients (female) and asked them if my father has some kind of relationship with them. There are other ridiculous stuff she has done prior to this but this one crossed all limits because it involved our business clients. She averages 20-30 calls a day to my father to check about his whereabouts and the people he meets. I have begged my father to get separated but he seems to consider societal status and the respect of his children and not the divorce. There's a lot of harrassment he faces at home, which I cannot mention here. I have considered calling the police but everytime I think of the embarrassment our family might have to go through and stop myself. Her side of the family is helpless and doesn't seem to bother much and it is of no use to get them involved. We are prepared to even consider a psychiatrist or get some other form of mental help for her. But she denies everytime and gets out of control when this topic is brought up. I'm in such a fix where I literally want to get out of home and go away to a place far off. But the thought of my father dying just doesn't let me do anything. I would like to know if I can file a complaint against her on the grounds of mental harrassment. Also, if not legal action, I would like to get her some mental help with some legal guidance.