Hi Joruth.
So sorry to hear about your difficulties. You sound as though you are doing your best in very difficult and painful circumstances.
Ignore Riakin. What a terrible post.
I can only speak from my own, similar experience, with my exH. Split 8 yrs ago. He pretended to others that he cared about our 3 children; reality was he cared about himself, and about finances. I had to spend years behaving very, very carefully towards him in order to not do anything that he could use as an excuse not to see the kids. He used them as pawns in a vile form of revenge towards me. Appalling. Yet I felt I ought to promote and support them having a relationship with him.
However, I wish I'd followed my instincts, namely, that he was a selfish man, obsessed with revenge towards me for our break up, and not to be trusted with taking care of the children properly. If your ex was not the father of your children, would you entrust them into his care? (In my case, the answer was no, yet I kept trying to persuade him to keep seeing them so that they didn't grow up without him. Big mistake.)
I didn't realise til last couple of years how awful he really was, when older 2 children have told me about their access visits: ignoring them during contact visits, making them responsible for care of their much younger brother, leaving them alone for hours in hotel/motel rooms when they didn't 'behave', did no homework, etc etc. Burdened them with full details of the divorce, financial, emotional, when they couldn't cope with such details. They didn't tell me at the time because they didn't want to 'upset me' - how heartbreaking is that?
During last 2 years I have been to family therapy sessions with both the older 2, now in late teens. This has been invaluable to all of us, and is starting to repair some of the damage done to them. Now they are older (very late teens) they both refuse to see him.
Yet on the surface he looks caring, professional, nice man. How appearances can deceive!
Maybe this is not helpful. I'm trying to say, follow your instincts, and look for help and support from good professionals. I'd include family therapy, or counselling via gp, among these professionals.
And avoid people like Riakin!!