AIO NSFW Idk what to do

I (17m) have had it rough with my mother (31f) for the past winter break. I've slacked off in school, she has been defending me from my step ma (32 f) and made a plan to make me catch up on homework, but I saw no point in trying to catch up on homework at times, and im not as productive as she wants me to be from time to time, and usually "made her look stupid," her words not mine, but i did what she wanted me to do for today. Had physical encounters with her, meltdowns and threats such as self harm and suicide. Physically im mainly defending myself but I also had to use force to stop her from trying to go all out on me. She's been fighting my step ma (32 f), whom she's in a relationship with for as long as I could remember around 8 years old. This has been taken a toll on me. I have been closing myself off, even when my uncle came home from jail for Xmas eve and staying with us. I can't sleep well, and even had a meltdown and tried to bash my head in with a spare guitar neck when berated for taking my time with an assignment due to how stressed i was, and was later on told "Go on, try bashingnyoure head in again, see if i care." Now mind you i haven't been able to sleep, barely slept, just happen to be hungry. Plus I told her 2 hours beforehand where I was before this convo. The household sucks to say the least. And I have mild autism so I'm not sure how to feel, besides anxiety and fear for the future.