Abusive Homelife; I feel so unloved and hated right now by everyone and it's stressing me out?

If your life is that bad then go to 'friends of the court' and ask to be put into a foster home. It would be better than the life you are currently living. It won't be for long since you will be 18 soon but get off the drugs. It will make your life go down hill fast and you don't want to pattern your life after your parents life if that is what they are like. You don't have to make bad choices and lower your own standards like they have if you are seeing the picture as clearly as you are saying. You also do not have to believe anything negative anyone tells you. I suggest you find a good church and get into a youth group there. Try an Assembly of God church. They have powerful youth groups and the kids are all great for friends and active in God's things. That will keep you motivated and may even help get your sister into God as well. God is the only one that can rescue you out of 'the mirey clay' as Scripture says it so put your trust in him and not in the drugs and cutting to get you out of this dilema. No one can make you do anything you don't want to do yourself. God gave us all a free will to make choices. It seems your family is making some pretty bad ones but you don't have to do the same. Start being the 'beacon of light' in your family and whatever they do, don't let it become something you take revenge on yourself for or cause you to get bitter in. Remember what Jesus did to those who crucified him... he forgave them while he was dying on the cross for their sins. Good luck.