My Mom's Drinking and Partying is Affecting My Mental Health

My moms been affecting my mental health and my financial stability. She’s been drinking and partying like she’s 20 but it’s only gotten worse. She spending my money on liquor and leaving all day, I don’t know what to do and I feel helpless. I just found her snorting coke in her kitchen, she doesn’t know I saw her but I want to confront her. Although I will bite my tongue for a little bit I need to talk to her about her behavior, she says it’s because of her bipolar disorder and maybe that’s true but she’s not taking any steps to improve. I just want to leave and never come back.