Must have been mean in my previous life

Hi there,
I sit here alone and scratch my head wondering what my daughter and I have done to deserve this.
I have a 10yr old daughter, her dad and I split while I was pregnant.
He got back with his ex who he said he wished our daughter was with.. there is a bit of a back story to the ex who I dislike more than a cockroach..but never let my daughter know my feelings.
Recently we found out her dad is leaving town (Happy about that) but things have just gotten so out of hand, and so mean.
My daughter came home and said her step mum was calling her some really nasty names.. I bought this up to her dad's attention who had a go at me, and said it was convienent timing due to him leaving and that I'm jealous of the step mum..(I have a partner, am engaged and have 2 more children). So certainly not jealous.
Her dad showed our daughter all of my messages, not his.. to make me look like the bad person. There was nothing wrong in the messages so I dont care, but it's the fact he showed her to begin with.
It has now come to my attention that her dad has called her a dumb c#nt, stupid, fat and has let the step mum do the same.. I mentioned something about this sort of language being verbal abuse and he has told her it's not abuse at all and he isn't doing anything wrong.
He has now started in on me, taking personal digs at my life.. saying things like her lastname shouldn't have been the name I was born with (changed to step dad's name), started telling her that her GPA is not her grandpa cos he isn't my dad (she didn't know that), that she needs to act like his last name because they are smart and my family isn't.. there is so much more that he is saying but too long to list.
But I mean come on it's been almost 11 years since we separated..
He says he is protecting her from me and my life (cos my siblings and I don't talk all the time), im a liar and that if she keeps going she will turn out to be like me.. He held his phone up to her face and shook it and goes don't be like your mum, a liar.
He has now told her that if she tells me anything that is said at his house he will kick her out of the family. "You don't bite the hand that feeds you" is what he said.
I found a note she wrote, it made my heart break into a million pieces at how a parent could be so mean..
Don't know what I'm seeking but need to clear my head from all of this drama.