@stressedmumOf3
I’m so sorry for what you’re going through. My DD went through a patch of sibling rivalry which was a fraction of what you’re describing and it almost broke me mentally. I think as a parent when you seeing your younger DC being hurt, there’s a very primal rage. At the same time it’s really hard to feel that rage for your own older DC. So mentally it’s so tough.
I hope you get the support you need. In the meantime, here are a few very small coping strategies which worked for me.
I think the key was that for us, DD1 could sense how upset/ frustrated I was with her, even if I controlled my words and actions, my expression and tone gave it away. These will make me sound like the worst mum in the world, but I’ve been where you’ve been so hopefully they might help you:
On the insides of my kitchen cupboards I stuck all my fave pictures of DD1. It was a physical reminder every time I opened the cupboards of how much I love her. It also helped her feel special
If DS2 ever broke or ruined anything of DD’s (small toys, sunglasses etc) I would buy a replacement the next day (sparklier if I could) and gift it from DS to DD.
Lots and lots of baths. I’d run a really nice hot bath, lots of bubbles, bath toys and maybe something special (bath crayons etc) and pop DD in. DS and I would sit nearby on the loo (lid down, sorry for TMI) and nurse, play and chat. DD was contained in the bath for half an hour or more and happy, i was supervising, DS was happy to chill w me.
Books: surely your DS can’t rip up board books? My DD was very anti books but what worked for us was to start w ‘interactive’ books. You know the ones with a puppet through the middle? She loved those. After a while she started following the story and we moved to pop up books, then slowly regular board books and now paper books.
Really hope things get better for you.