@birdbandit "He is not the good liar of his imagination, he is taking credit for people being polite. I don't think he is anymore convincing than the average flat earthier, or person who believes the queen is a lizard."
Just remember you know what happened and really you and your children are your priority, if others are polite, fine, if they believe him, fine, if not fine. Try not to allow his shenanigans to matter to you, if you can. I know it must be hugely difficult.
"But every time he gets his victim hat on, I'm the one who has "trust issues" that I'm mental, forcing him into depression etc. " But you do not have trust issues, you just don't trust him. It's not the same thing. Do you need to engage with him? Are you living apart now? Is he engaging with you via email, phone, in person? Sorry, can't remember the exact details.
"They spent time dealing with his porn addiction, but again that's my fault. Is he saying it is your fault to you or to others? I think if he is telling others you could either just ignore it or set the record straight only if it comes up and you need to 'defend' yourself. If he is saying this directly to you, can you disengage?
"He wouldn't have a porn addiction if I weren't so mean, it makes him sad/depressed, and porn is an escape. During his stay he wrote another letter which detailed his addiction, chatlines, forums, how many hours a day etc. It was embarrassing to read, and I cannot believe it was anything other than the tip of the iceberg." What response does he expect from you reading all this? What response will you give?
"I cannot believe I was dim enough to marry and have children with this grimwad of a moron." That's the past, we all make mistakes. But you have your lovely children and now you need to focus on the future. They can indeed be kind to him without buying into his circus.
"He's a weird combination of a huge ego, where he has placed himself on a pedestal, but it is a fragile veneer and cracks easily. Then you see the anger and the self loathing." He sounds very dangerous, can you limit how much you engage. He may find hep when he is ready to move on or whatever. 