Your parents dont need to make money and face things while their parents are supporting them with the house and with your income all seems fine to them. Paying for rehab was a big thing. Does your money go to support your moms drinking? They are using you because they can. They are using their parents because they can. Have you spoken with your grandparents about what is happening? You are in a hard situation. They are grown ups. What do you think would happen if you did move out?