What should I do ? Please help me

[Justaphysicsnerd]

I feel like the LTT forums are the place where I can talk and speak freely, even more so than my own house atm. Now a bit of context, I am a teenager who is in a dilemma about what to do with his life ? So, the story goes as follows :
My hometown is well....basically a small town, so I had to go to another city for studies. Now this city is say about 1000-1200 Km away from my town. And where I live trains are much more common than flights. So as you might have guessed it, it takes approximately 2 days to get from my hometown to the other city. (All this information will become relevant in a second) I had gone to this city in 2019 and began studying there (obviously I had to stay there too). I still remember to this date, on a September Saturday evening my mother called me, the conversation began as usual. But I soon noticed that my mother's voice was a bit faint like she was talking to me in secret or she was sick or something, so I asked her, why do you sound so sad ? She first cried a bit and then why I asked her again, she informed me that my elder sister had beaten her that day while my father wasn't at home. I became immediately worried, till this day I wasn't worried that while I am away nothing would happen to my parents. But now there was a threat that someone who had been dependent on them their entire life, could beat my parents ! This obviously affected my studies for a few weeks or a month. I couldn't discuss this with either my teacher or my mentor or friends. The only thing I had in my mind during that time was, what should I do ? How can I save my mother ? You might have read it in stories only, but I actually had a few sleepless nights after that conversation due to the fear.
And If you are wondering yes my elder sibling is aged way past 20 years, so yeah what she did that day was a crime !

Then came the year 2020, so lockdown and quarantine begun. I had to return to my hometown before the quarantine orders would begin. To my surprise, my father had still kept that woman (lets call her B) that is my elder sibling who beat my mother, in his house. Now, when my mother had talked to me in September of last year she had told me to keep it a secret and not let my father know that I had become aware of this event. A few weeks passed and then B beat my mother again, this time infront of the whole family. But then also my father did nothing. My studies were affected again as a result of this. And what I was surprised to see that the very next day, my mother went to B and asked her politely to come for breakfast. I was shocked, I had told my mother she shouldn't talk with B and at least inform police, because now I was a witness. But my mother didn't do. B started beating my mother on a semi-regular basis like for the 9 months she was in that house (after which she went to her college), she had beaten my mother for 5-6 months, once every month. But all the time my mother would side with B, whenever discussion arose regarding B's behavior ?

Now, think of me in all of this, a teenager who loved his mother so much. My studies got constantly affected for almost the whole year of 2020 due to the above described events. And I was also very sad and horrified that my mother went to B every time and talked with her. And to be clear, B had sometimes even spit on my mother's face and beaten her brutally. Not only that B, also used to prime my mother towards me and due to that I wouldn't talk to my mother for weeks. And once to protest that It is completely wrong to keep B in the house and talk to her, and that my parents should call the police, I had gone on a hunger strike for 27-35 days. But they still don't g*ve a f***. My mother still sides with B. Due to all of this trauma of course I had a lot of stress. In fact during the 9 months B was in my parent's house, I had clearly warned her not to come in the room where I was staying. But she would still try and enter the room or take a peek at time, which gave me even more stress. You see my room is designed in such a way that the place where I sit and study is directly in front of the door. So whenever I was there studying on the desk, I had constant fear that she would bust through the door and enter that room and beat my mother, as on the day she beat my mother in front of the whole family, it was in this very room.  As you might have guessed by now, I had developed a hate for B and didn't even want to see B's face. So I didn't go near the area where B was, that also gave me another problem. B used to roam around making noises so that blocked me off to this single room. Not only that B would also insult me by calling me abusive words, in which my mother would support her. And she used to do all of these things constantly (priming my mother towards me, beating my mother and calling me abusive words), so one day in anger and stress I also called her and abusive word, which is basically like M****F**** but remover Mother and add sister there in my language. When word struck my mother that I had called B that word, she primed my mother even more and my mother beat me severly that day.

My parents supported her in that she should beat them, which is wrong ! Now, due to all of these traumatic events my whole year of 2020 has been ruined and I have exams in February what should I do ? I can't remember a single thing properly. What disturbs my mental temper even more is that my mom, now video calls her everyday and talks to her ? Even when I tell her that she should think what a child feels when someone beats his/her mother and his/her mother keeps talking to the person who beat her, but she puts it off jokingly. I told her It is a crime what B did, but my mother still says B did nothing bad.

 

Several times while arguing with my mom that B is wrong and you shouldn't talk to her. My mom told me "I don't want to see your face, I just have to see It because you are in this house !"

This puts me in a dilemma. that am I the wrong one here ? and what should I do ? as my whole year got ruined ? My studies are now ruined as the year of 2020 was very important for my exams. What will I do ? If my mother keeps talking to B. I hate my life and I was having thoughts of either eating rat poison which is in the kitchen on the shelf or jumping from the roof of the house. As you might not understand but where I am from the study of class 12th (year 2020 for me) matters a lot for my exams in Feb (the exams are called JEE) ? What I should I do now, because I feel like the whole year of 2020 has been ruined for me and I want to die because my mother has told me she wouldn't stop talking to B