Harassment by Parents and family members

I am a Hindu girl 22 yrs old still in the second year of my graduation. I am an adopted child. My step-parents have always mistreated me and harassed me especially my mother. She has always beaten me and abused me since I was a child. Now my father is no more and I am alone in this house with my mother and her 3 sons. Two of them has molested me since I was very little. My mother knows about this but she didn't do anything ever. Now I am all alone and the house is on her name. She doesn't give me any money not even for my medicines. Sometimes I don't get food to eat. I have been on the verge of Suicide from very little. Now the elder son is trying to sell the house and they are just ignoring me. I don't even get money for my college fees. I am very alone. I don't know what to do. Sometimes they even threaten me. I am afraid of her sons. I don't know what to do as there is no property on my father's name and the house is on her name. I don't know what to do. Please guide me.