It's my second year of highschool and everything's been hell at home. My older sister had been always saying that family came first when we were younger and promised me that. But now she's been getting into relationships and sleeping around even when my mom told us countless times that she will not accept any pregnancies when we're still living at her house.

Last year was traumatizing for me and my other younger siblings (one in primary school and one still in kindergarten). Me and her always argued and it always leads to her getting physical or threatening to be physical. One time, I finally had enough and attacked her when she threatened to hit me. We had to be broken up by my grandpa and that's when she tried to get a knife from the kitchen, threatening to stab me.

Her ex bf broke up with her because apparently their relationship was too toxic. It became so bad that the police was called and she was brought to a mental hospital. Only a week (or month) later, she had scratched my autistic brother that he started bleeding. There were so many arguments that she decided to call the police because her new bf (the broke up too) encouraged her to call the police. She kept arguing with the cops and even threatened to take her own life again yet the police couldn't care anymore since she kept using that threat.

Now, me and her keeps arguing again and complained to our mom about how I've been ignoring her. I've been told countless times to just ignore her because I've completely gave up on her mom I was treated like her therapist and I've begged her to stay home but I just can't deal with her anymore. Everything was fine when she's not around but Everytime she is around, there are arguments or injuries. I honestly don't know what to do anymore. I've been told to ignore her but that causes problems but when I do pay attention to her, there are arguments.

Am I the AITAH for ignoring my sister when all I want is peace in the house? And if I am or not, can I please have some advice of what to do?