Your mum has to report this to 101 NOW!
You both need to get some protection from the courts!
This could be deemed as indirect contact to you iirc.
The fact that he's menacing and accusing her is very telling. A normal man would be at least saying sorry, how can we fix this.
Your ex is a shitty little abuser and he'll only ever get worse.
Your comment about talking with the other women there is why I always advocate doing the freedom programme in person, as you get to hear how much you've all had in common.
I always find that when we see the shock and horror of others at stories that we've normalised, and they see our reaction to ours, it helps us see the extent to the abuse to which we've been subjected.
It's frightening at first, but helps us learn to feel sympathy for ourselves. Note I said feel sympathy for ourselves not sorry for ourselves. BIG difference.
Do you think he saw you and waited until you'd gone to target your mum? You know what that means, don't you?
That seeing your dd is not what he wants, it's control of you, your mum and whoever else. He's not spared a single thought for your dd. This is all about him.
He's dangerous. Your mum has to call 101. She does this to protect herself, and it will actually help you too, as. It will go a long way in court that he did this. It will keep your dd safe.