What should I do? My family lacks structure so badly and im the only one who cares?

Your mom needs to grow up. She chose to have kids so she needs to act like she did. Your brother and sister need to be disciplined for all that crap. Ur sis is really mean. Next time she says that ask her, "What if I did die?" Maybe that'll bring her some sense. I think every time your brother curses you need to spank him. I know that sounds rediculous but he needs to learn these things from somebody. I know you have responsibilities but you need to sit down and talk to your mom about this.