Father harassing us mentally

Hi, My parents have been married for 27 years. My father has his own business and my mother is a housewife. My sibling is a student and is unemployed. I am working from past 1 year and pay for my own expenses. My mother was diagnosed with brain tumor sometime back and treatment for the same is still on going. My father has been continuously harrassing us from past 25 years. He has forced my mother to get dowry or money from her parents or earn and contribute in family expenses. He earns well and makes leisure trips atleast twice a month. Now he has started harassing me to pay for household expenses and has been forcing all of us to leave the house. He abuses us daily and has been doing so from many years now. My father has had many illegitimate affairs in last 25 years. Please advise what should be done in such situation? We do not have any place to go so leaving our house is not an option. We are scared for our lives so can we legally ask him to shift to his other house. Also, can he legally ask his family to leave his house? He does not give any money for household expenses and is least bothered about my mother's health. We do not have any idea or access to his savings or other properties.