You are not a failure. Going on antidepressants isn't failure . It is you looking after your mental well being so that you can be the strong woman that you were before this trauma undid you.
I have tortured myself thinking things like you ,imagining stuff he did. It absolutely does you no good and you will never know the answers you seek.
He seems to have lost his goddamn mind.Impossible to figure out. Wonder if his ED contributed to all this. Men are so sexually oriented , I think , it kind of defines a lot for them. If he couldn't perform with you, he might have felt ashamed . And you were with him when he had a healthy sex life .
It might suit the OW to be in a sexless relationship. And let's face it , it's not exactly going to be great or spontaneous.
This OW seems to be a cold hearted bitch . Takes some selfishness to abandon your kids . This will probably only last as long as craziness does.
They deserve each other, two dysfunctional bastards. It's not love , they don't even know each other.
But whatever becomes of that drama , please don't let him back. He has abused your trust , been cruel , lied , cheated and had no consideration for your feelings. And has also dumped his kids. Hope you can see what an unappealing sleazy, selfish bastard he is.
You are way too good for him and really dont need such an nasty person in your life.