Something about my mother angers me everytime she asks me anything
Ever since 6th grade we would revise the material I needed help with together, and because I have a sister that has more difficulties with remembering she'd always spend more time with her. And every time my sister would get something wrong she would yell. Eventually I couldn't focus on the things i learned as well(7th grade) and she started yelling at me too. It wasn't that she wanted to, she has anger issues from her childhood as well. So, because of all the fighting and crying and stress and yelling, I fell into depression in 8th grade to the point that I couldn't even care for myself. My mom started getting angry because I couldn't care about myself either, I gained weight which I'm still struggling to lower because food ended up being the way I cope. She would ask why I do certain things in a judging manner and I've become shy to even answer, I rarely had an answer. I always said "I don't know" to lower how tense it felt. And I ended up isolating my problems. I tried talking to her, and all I got was her turning it on me and her venting about her problems and how hard it was for her. And it was always "well look at me how do you think I feel you always do this this and this" so, I stalked talking to her about my problems and coped myself. I cried alone, I calmed down alone and I didn't ask much from her. A few years later, my sister ends up having problems with school again, and I haven't seen it be resolved any other way other than yelling and crying from both of them, and I have to bear it and hear it all the time. So at this point I'm trying to help both my mom and my sister, my sister out of anger lashes out at me and my mom tells me to not try resolving because "it's not my responsibility" and that's how it's been since then. I'm so used to hearing my mom's angry and judging voice, it's unusual for me to hear it normally. I start to forget to do simple things even if someone mentions it to me a few minutes ago because I feel so tense all the time and I genuinely can't take it anymore. Now, everytime my mom asks me something or tries to talk to me about something, I hear that tone in her voice(even though it's her natural way of speaking) and I get so triggered I just lash out at her and say it's not important stop asking me. Please if anyone can tell me how to improve I genuinely need it. Am I doing something wrong? What can I do about this situation? How do I calm myself down when I'm in such a hard environment?