Keep busy. If you can, throw yourself into getting a good education. This will allow you to get a good job/career so that one day you can take care of yourself without your parents. We have a teenager that we are encouraging to receive a good education. Dad and I may not always be around to help out. It seems you can not rely on anyone else but yourself now days.
It is sad that parents can actually threaten their own child. I wouldn't treat a dog that way, much less my own child.
Sorry that you are struggling.