Your update is promising, as you sound quite level headed.
But I’m struggling to understand this:
I just am struggling with baby tantrums and how to deal with it and this is all new to me.
You’ve had 2 kids before, so why is it all new to you?
Is it the fact you’ve got 2 bio DCs and now a shared one and you don’t know how to deal with that dynamic?
You and DH should be modelling how you want the girls to act.
If you don’t want them laughing about the situation, then don’t laugh yourself.
They want to help but don’t know what to do, so just copy you and DH.
They shouldn’t need to be sent to their rooms because you and DH can’t cope with a 3yo between you.
There is something odd about this dynamic that I can’t put my finger on.
You and DH are both struggling with your child’s behaviour, to the point DH shouted, swore and put his hands on a child.
(And all they were doing was copying you and DH).
Little kids having tantrums are incredibly difficult but I’m struggling to understand how you can both be so stressed out when there are 2 of you doing it.
How did you find the older ones at that age?
Do you and DH ever just take in turns to bath the LO or do you always do it together?