Mental/Financial Harrasment and Suicidal threats by father.

I am 28 year male(Unmarried) and I live with my parents. My father, age 61 is a retired Police officer, is harassing my mother for last few years. He almost drinks daily and always under influence of any kind of addictive substance(I am not sure what he takes). Many times he has tried to physically abuse my mother in front of the family. All these years my mother has hoped that he will change and has taken care of him but things are getting worse day by day. My mother is suffering with kidney infection and has been in and out of hospital many times. Not even once my father has paid for her treatment. There is monthly expense of 3-4K on medicine for my mother but for last few months he refused to give. Now the main reason why I am looking for expert advise is the incidents happened recently. Last week my father started accusing my mother that she has an affair(after 35 years of marriage, shocking right!) and he claimed that on the basis of dream he had(all the drinking and addiction has made him delusional). Now he started swearing and insulting my mother in front of the family because of this. As a last resort we have to take my mother to my elder brother's home. She stayed there for 3 days and meanwhile all the family member tried to calm him. On the 3rd day(which was last sunday) we decided to have a family meeting at my brother's home and hoped that he will understand. But he refused to come to the meeting and called my brother saying that he is taking his life and sent photos of letter(in which he blamed everyone and my mother) and the hang he made. My brother, Mother and 2 uncles rushed to home and as they entered(Door was open) they saw him standing on 6 ft metal stairs and holding broken rope in his hand!! And started saying that he would have been dead if we came 5 mins late. After this stunt of his, my mother broke down in fear of every one has to suffer because of that and agreed to stay at home. But now I am really concerned and afraid of her safety as I am on job most of the day and he normally drinks and abuses her during day time. My brother and I have good jobs and we are capable of taking care of my mother. We called 181(women helpline number) yesterday(24th April 2017) but there is no response even after 24+ hours after the call. They took initial information of the issue but didn't took any names or address and told that they will contact back. I am really shocked by this response. I need help and guidance what should be done in this case.