So, since last August, I discovered that my sister (who is 14, I am 17 since Jan) had been self harming. By 'discovered', I mean she told me, yet refused to let me tell my parents. However, later that afternoon, I broke down crying, unable to cope on my own with the news. My mum came over and eventually discovered the truth, and immediately told my dad. My parents aren't bad people, but just don't know how to handle things like this, regarding mental health. They confronted her about it, and eventually got her to a doctor, and then I thought everything was going to be okay.
However, a few months after this though, around December, I received a message saying that my sister had been telling this lad she was bleeding out in her room, and that she was going to kill herself, and in all honesty, being quite vile. I went immediately to my mother who called her down and asked her calmly about it. My sister acted out and was quite horrid towards us both, and eventually started to scream she hated me for telling my mother. This happened again a month later, as well as 2 weeks again after that.
After that, I was trying to not say anything horrid to her, and to be quite calm for my mother's sake, as my dad is a truck driver and works away a lot. Then around 1 month ago, a friend of mine came up to me and told me my sister had been saying to a load of people my mum was abusing her. I went and asked a bunch of people who I knew that some were her friends, some were just in her year, and there were too many people who told me the exact same as my friend, some even having exact details of conversations. I went home that afternoon and confronted my sister, asking her if my mum WAS abusing her (I thought this to be false but felt like I should ask just in case) and my sister denied ever saying it. I then went downstairs and explained the situation to my mother what happened, before my sister posted something online, asking people to stop saying she had said it. A lot of her friends commented underneath saying she had said it, and she and my mum started to argue again. I left the room at this point, and was very upset. A while later, my mum came up to tell me she wanted to explain, and I told her straight out I wasn't going to stand being blamed again for this. At this point, I broke out crying. She hugged me, before hearing the door slam downstairs - my sister had ran out as soon as I needed some comfort. I then packed a bag of stuff, and left for my boyfriend's house.
After I spent the night at his, I went to work and tried to carry on as normal. I went home, refusing to be pushed out of my own house, and haven't talked to her since.
Is this being selfish?
I just feel like I am on my own through this, and like I have no support anymore. All while these incidents have been happening, I have been struggling with an eating disorder and an anxiety disorder, suffering largely over the past few months with panic attacks, as well as 2 pregnancy scares, yet I haven't been telling my parents as I feel like they have enough to deal with already.
Since I left, I haven't been talking to my sister at all, and recently my mother has asked me to try to make amends, yet I still feel angry at her for doing this to us all and for not even apologising to me or my parents properly. There's a part of me that doubts she's even properly sorry.
Is this being cold-hearted/selfish though? Does anyone have any advice they could give me please? I really don't know what to do anymore.