Are we the problem or is it just her?

My name is Robin and I am 23 years old. I have a 24 year old year sister that I have never been close with. We have never really been into each other’s lives or close or however sisters are supposed to be. I don’t know why, but it has always just been like that. Growing up, during our teenage years, she was never really around, always wanted to be out and having “fun” never really wanted to be in the house, always out of town with friends partly because there was always fighting going on, between everyone especially fights between my mom and dad. Our house was never really somewhere any child wanted to be. I am only one year younger than her, you would think we were the best of friends but were not even close. We go on periods where we just dont talk because she upsets me so much that I just want to completely ignore her and pretend she is not even there. But its like she forgets what happened and starts talking to me again first. So many years its been that way and I feel like I am losing my mind.

It is almost like she craves for drama, if there is no drama she will make one. she is always so angry, so mad all the time, and when she is happy, she is the happiest person and its such a delight to see her smiling because she never does. She has absolutely no patience. She gets irritated sooo fast!! and at anything and everything and anyone and in general its like she doesnt want to live in peace or be happy. She picks fights with everyone, friends, family, she hates me so much and I dont know why. 2 years ago she had a miscarriage and asked me and my mom to not come see her at the hospital but everyone else could. At the time she never told me it was a miscarriage because she couldnt let my parents find out she got pregnant, so she claimed it was a cist, it was not til the year later that I found out it was truly a miscarriage. When she got back from the hospital, she beat up my mom, anyone who got in her way had hell to pay. Her eyes looked crazy as she was filled with rage and anger all the time and never slept. She wet the bed one night and I didnt know anything about her condition I just figured it was same old Sammy, just anger management so she asked me to help her after she cursed me out and almost beat me up, so I said no way and she recently told me that, that was the day she knew I was not her sister and that she will never forgive me for that. But if I had known that it was a miscarriage, and I had known she was on medications, if I had known anything I wouldnt have rejected her help with the bed. But she kept me in the dark about it, about everything, she will tell her friends everything first and maybe if I am lucky she will confide in me way later in the future.

She has never had one real strong good friend. She has a problem with every friend she has ever met. I introduced her now to my friends so we now have mutual friends. She cannot keep anything to herself, she tells everyone my family’s and her own business. When someone disagrees with her, she goes crazy, like were attacking her. She hardly sleeps, always listening to music so loud all hours of the day and night. My dad does everything for her, she has always been the favourite especially to him, anything she wants and needs he is there for her and she still continues to treat him like garbage to this day even though she is the only child out of 6 of us that he will do anything for. At 24 you would think she would become an adult and become more wise and leave your sick old parents alone, but she will never leave them alone. She called my mom and dad every name in the book, even physcially hit them on multiple occassions and I cannot accept th abuse she is causing them, if it was to me I wouldnt care as much because then I would block her out, but my dad is really sick and so is my mom. I know she takes some medication but I dont know what they are. She just completed her nursing degree and ever since she got into nursing, she has discovered every type of meds. She got better 2 years ago after the miscarriage but everything looks like its happening all over again. I dont know what to do, whether to salvage my sanity to get her better or to just ignore her, which is what I’ve been doing the last 22 years. I hate they way she treats my parents, I hate it. We have 2 younger sisters that I spoil and take care of because I dont ever want them to be the way me and my older sister are. What should we do. I feel like I am losing my mind and going crazy now Please help