Don't text your ex about it, take her to the GP
BTW he's acting like nothing has changed because nothing HAS changed. For him. He checked out of your marriage months or even years ago.
In his head he has a little story which goes
" yeah our marriage has been over for a while now. Meeting OW was a symptom not a cause, it was because I wasn't getting my needs met at home.
So I felt I had to be honest with I Iwas a girl and wanted to discuss things calmly . But instead she went crazy and chucked me out.
Now I'm single again I'm working and playing hard and sometimes it's hard to fit the kids in. But I do my best and iwasagirl doesn't even appreciate what I do for her. She difficult and demanding and expects me to jump every time she sends a text. She doesn't seem to realise that I have a life now, all she cares about is the kids.
I try to be kind when I pick the kids up but she won't even chat to me. I just want us to be friends"
It's all bollcks of course but that's the story he's telling himself and his family. As OW tells him what a great guy he is and a wonderful father.
Because otherwise he would have to face the truth about himself.