Struggling with anger and hurt

Hello,

I'm really struggling a lot with my family. It's so complicated and I feel lost in my family because no one seems to understand where I'm coming from or even my levels of empathy and compassion.

My mother is emotionally abusive and most likely has undiagnosed BPD due to extensive trauma and emotional neglect/ abandonment by her parents as well as being physically disabled so has lived with awful pain from the day she was born. Her own father was also, now days, we would say both emotionally and physically abusive.

So she has had a lot to deal with in her life but she also believes that there isn't anything wrong with her and has never acknowledged her trauma so because of that she's filled with a lot of insecurity, trust issues etc. So, my sister and I and my father has always had emotional abuse from her. Being told that we're arseholes, selfish, stupid etc on a daily basis. (I'm no longer living in the same country as them).

What I've been struggling with is that my older sister has gotten away with so much more- the rest of the family (my brother and my father) always say that she had it worse, and we both had the same abuse. The difference is that I handled it differently, why, I don't know. But also, if I overreact with my mum or whatever, my dad would always call me out on it, to say that wasn't right. And I get that. But my sister never had that. I've had times where my sister has said nasty stuff and I've reacted and my dad then has a go at me for defending myself.

My dad has always been blinded by my sister and my aunt, his sister, has pointed out that she can be incredibly selfish and entitled, which she can be. She's living with my parents with her two young children. She hasn't had a job for years and basically leeches of them and yet whenever someone points out her position she then plays the victim card. My dad has only just recently started to wake up to the fact that my sister can be wrong and because for the first time in her twenty+ years, she's been called out on her crappy behaviour by her father, she's reacting badly.

I have a lot of empathy for my mother and what she went through in her life. And I have learnt now that doesn't make what I went through, the abuse from her any less validating. It's just that I can separate my shit from hers. But my sister has always had allowances made for her. She's six years older than I am. And I've been very interesting in psychology in my life and have studied mental health, so I sometimes think that our roles in a dysfunctional family have switched. She behaves like the youngest child and I behave like the eldest daughter.

I have empathy for my sister too. I understand what's like to go through the abuse- we had the same. Being filled with chronic anxiety, self-hatred, insecurity, a lack of self-belief and confidence. Generally thinking that you weren't going to amount to anything... I get it.

My parents from a young age, depended on me for emotional support and I often feel responsible for pretty much everyone in my life and the older I get the more I realise that isn't true. But my parents are visiting at the moment and it just brings everything back up again. And I end up really struggling.

As well as the caretaker role that I had in my family, I was also the invisible child. They would come to me to seek support and then whenever I said something that they didn't agree with, I was told that I didn't know anything. And was so easily dismissed. I feel angry, confused, tired and over it. I want to cut ties but I care too much. :( No one from the family seems to validate or understand what I went through and how much the family relies on me. I don't know what to do.