Need Help

I don't know what to do. My Mom asked my Dad if he had put his blanket by his side of the bed. At first he didn't say a thing until she started yelling. I cry every time she yells at my Dad or I. I remember one time she yelled at me and smacked me across the face and my nose started to bleed. It happend once later and I was about to call the police. My mother said that if I called the police, that I was going to not come back in to the house. There is no way that she was going to do that to me. I can have her arrested for physical abuse. But I don't want her to call to have me arrested for verbal abuse.