I need advice

My mom is kinda an asshole, to me at least. She is an older woman who has been in an abusive relationship with my drug addicted dad for a few years, but always came back to him and brought him into our lives. Now, whenever I talk about my boyfriend she makes a disgusted face, rolls her eyes, and starts to mimic me. She has called him a girl on multiple occasions due to the fact that she doesn't see his personality as "manly enough". I ordered food today and told my mom what I was getting. She asked "really? You're getting all that". I like to save food for the next day so I don't have to cook and I'm pretty skinny as well as sick right now. My older brother who lives with us seems to not be able to know how to clean up after himself (he's in his mid-twenties). He leaves hair everywhere, all his shit on the counter, etc... I told my mom to talk to him because I clean the bathroom. She tells me she will and never does. I just want to be happy in my house and in my own body. If I could move out I would. What do y'all think I should do? Am I overthinking her actions? Please be nice I'm going through it right now.