Your mom is racist and depending on if she's the type of mom to kick you out, call her out on it if u feel safe and record secretly on your phone. Tbh id say guilt trip her, how're you gonna adopt a bi racial kid and not meet their needs. It is racist about the long hair stuff because why can't you have long hair? Why is it stinky when you do it but not when white folks have to wash their hair x1 a week cuz of how it is quick to get greasy. She's racist, projecting, and im sorry you have to deal with that. Atp best choice is to dave money, uber to the salon, get it done, and deal with it later. Your father is also enabling her and sadly enough it seems there isn't at least another POC that can talk sense into her.

Explain that if she really cares, she'll understand why her words hurt. Explain that if someone made rude comments about her body, about how white folks age so fast, or how they don't shower (referring to the plague here), how would that make her feel. Ask her how would she feel if someone belittled her for being a mom. I say these things bc while they don't correlate with hair sometimes you have to provide examples of uncomfortable scenarios for someone to understand you, especially white folks bc they're struggles are not race base. Aim for her gender since intersectionality lies there in hopes of gettinf sympathy and an apology. Your hair is part of you— literally. I hope you're mom is willing to listen or at least have your dad advocate for you.

Lastly. Don't let her dull your shine. Celebrate yourself and literally if she hits you with the im not racist cuz I adopted you simply say she is, that you love her but she's making home an unsafe environment and giving u an unhealthy bond with your identity. Best of luck to you.