Im 17yrs old and idk how to cope anymore

I’m really not sure what I’m even aiming to gain from writing this post but I’m so exhausted and sick of living my daily life. I just genuinely need to get this out of my brain to people that understand exactly what this feels like.

im 17yrs old and for my entire life up until i was 15, me and my older and younger sisters were chronically abused by our mother. she verbally, physically, and emotionally abused us since we were infants. when I was 15 she kicked me out and I have lived with my grandmother since. (she is so much healthier and better then my mother and I am incredibly glad to have someone like her in my life to help guide me through everything)

Im in grade 11 and I cannot get anything done anymore. I can’t write down anything, I can’t focus on a word anyone says to me, and I find no joy in even just BEING in the classroom. idk why this is such a big issue rn but it is. it hasn’t always been like this.

i have frequent and violent nightmares genuinely almost every night and usually I have more then one nightly. every time I have one I wake up replaying every single aspect of the dream and remembering exactly what each piece symbolizes. I dont feel like I can lean on my bf or my friends or my family because everyone is sick of hearing about my mother. (she is abusive to every single person in our family and has fallen far down the alt right rabbit hole and hasn’t been even remotely normal for years. she harasses strangers in our town and causes frequent uncalled for confrontations with family members, and strangers in public places, and online. ppl I do not even know have negative experiences with her. my entire town knows how crazy she is)

idk where im even going with this but i just feel debilitated. all I think about is what she’s done and how she STILL has custody of my 11yr old sister. I never know what she is doing to her or our many pets, i constantly think about everything she has done to me and my sisters and why she did that. I don’t know how to exist anymore. I don’t feel like a normal person. I feel like a monster trying to pretend to be a human. I am just so distraught and confused and I feel so alone.

im in therapy rn and ive been to MANY therapists but i only get to see my current one maybe once a month or so. I just don’t know what to do with myself anymore.