Being harassed by own parents

I'm 17yrs old girl and I'm the youngest child of my family. We Live in a nuclear family. My elder brother is 19yrs old. My father is a business man and mother is a house maker. Father is the only earning member of this family. He harass us so badly and mentally torture us. We can't live peacefully in our own home just because of him. He doesn't give us money even for needful requirements like for grocery school fee transport fee. Not a single money is given by him to us to maintain our living.He spends his money on those things which are not required. Like he eats from outside everyday. He nor even drink water from home. He everyday purchase water from outside and drink. He just waste his money. We have already borrowed money from local store and some relatives for our needs. But this can not go so far. We can't survive in this way. My mother is not able to earn as she is suffering from some severe disease. Me and my brother are just students. Please help me out what to do. I also want to divide his business into 50-50. And then we will manage our living. Pls help me out with some suggestions what to do.