Got called a “selfish c*nt and disowned by my family”

Let me cut a long story short, my sister is 37 weeks pregnant, my daughter was still born a couple of months ago, she was born at 23 weeks with trisomy 18, Edward a syndrome, she died in my arm an hour after birth, my sister wants me there for her birth, I can’t do it, I cannot do it, I can’t even come close to thinking about it, I’ve explained to her the trauma is so fresh for me and I can’t be there and see another healthy baby brought into this world, and to sum it up she told me if I’m not there then I’m not allowed to see my niece and I said if that’s truly how she feels and she can’t understand my reasoning then so be it, fast forward to an hour later I was added into a group chat with my immediate family and some of my sisters husbands family and friends and they all come at me HARD calling me selfish, a cunt, a fat bitch, inconsiderate etc etc i kept leaving the chat and they’d re add me so I turned my phone off and my mum showed up at my door and called me a spoiled brat and that if I didn’t be there for my sister I was no longer a part of the family, and that I should be grateful I already have a healthy son who’s not got any problems, I said the same as I said to my sister, but a little more aggressively, fuck you and fuck them too, and closed the door. Since then I’ve been blocked by everyone in every social. My family have always been arseholes to me and toxic af but this is a whole new thing. I cut them off for around 3 years and reconnected about a year ago, and now I’m done with them again.