Okay, i am the oldest, and ever since i was little I've hated my father. I've basically watched him destroy us?

My father is a diabetic, he wouldn't be if he would've changed yrs ago... He (at the worst time) would drink a 24 case of pepsi a day! And smoke 2 packs of cigarettes a day, as a diabetic!!! He would go into rages because of all the sugar in his system. I remember him trying to beat my 7 pound dog to death when it was a puppy and learning to go outside when it peed on a mat, I had to physically stop him. Another thing you need to know is that he is so unhealthy he is 6 ft 1 and ways less than me (his 17 year old daughter!). We moved away from him for a while, but he didn't change and go so sick that they had to amputate his right leg! I had to buy him a bunch of stuff, and I was ready to just deal with it, but it is so hard to do when I know he won't change. He keeps calling me disrespectful and ungrateful, when I pay for a lot of bills and bye food, and help out the fam. My mom is starting to get depressed. He tried to beat me today with his prosthetic leg on, I just forced him to sit in his wheel chair, I don't want to hurt a cripple!!! Help me out please!!!