Thank you to everyone who has given me advice so far - I wonder if anyone would kindly give opinions on the next part of the saga:-
Following the ExH request to talk with me privately, I texted him back and asked him to put in writing (text or e-mail) what he wanted to talk about. He didn't ever reply.
I have seen him at pick-up time during the last two weeks, and he has been pleasant and courteous. His GF has been there, so I presumed they had sorted out their differences and back in a relationship again.
This morning I collected DD and she was clearly upset. I had about 10 minutes with her before she had to go to school and she told me that the GF had told ExH what DD had said to her about the reason our marriage broke up being that I left him because he was controlling and bully.
The GF has now finished with him again and last evening ExH was very unpleasant to DD and made her cry. He told her that she was the reason for him and his GF for splitting up, because she told his GF why her mum left him and also that she herself (DD) found him to be controlling too, and didn't like being with him.
ExH told DD last night that one day, he would tell both her and her brother the truth about what happened between their mother and father, and that everything I have told her was distorted or a pack of lies.
Because both my children know only too well what he is like, having experienced him, I'm not overly worried about this. The other thing he said was he's been to see his former GF from whom he split in 2013, who is a very nice person, and who contacted me by e-mail in 2013, after she split with him to find out the reason I left him. I was very reluctant to say anything to her as I feared for my safety, but in the end I told her without going into detail, that he was a controlling bully and he had got me to self-refer to a psychiatrist who told me I was not crazy. This lady said she had felt all along that there was something not right about him but she had deluded herself because she really wanted him as her BF.
Now, this previous ExGF has told ExH that I have also told her he was a controlling bully, although she made it crystal clear that she contacted me and got the information, not me volunteering it.
So ExH is extremely angry with me and has told DD that I have effectively interfered in both his last two relationships. I know he will try and get me alone and "have a go" at me about this at some stage, but my main worry at the moment is for DD.
She still feels she should carry on going to his house for 3 nights per week, but I can see she doesn't fully want to. I think she is torn because sometimes he is great fun, and she does love that part of him, but also his behaviour often makes her miserable.
I keep hearing her words from this morning - "it's all my fault they've split up, I shouldn't have trusted his GF. He's devastated." as if he didn't contribute to the situation!
Up until now I have left it to her to let me know when she is ready to stop going to his house and that I will entirely support her when that happens. Should I do more? I am conscious that ExH must be feeling angry that I am interfering in every part of his life, but if he didn't behave in this way and get himself into these situations, he wouldn't be there.
Thanks for reading!