Hey K,
Thinking of you all day. You must be terribly shocked, how awful for you. Its the scale of it, you are right, of course you are shocked, stunned,hurt and cycling over things. I noticed you said

"She too, apologized to me for telling me once during MC that I was stuck on that woman and jeopardizing the reconciliation. She told me to focus on now and forget the past and future. It's hard to do. She told me that he created in his head a story about our M that allowed him to act free of moral and ethical boundaries."

Ok, at last, she takes your side and apologies(she never did in MC!!) but.. I dont agree with her to just forget the past and focus on now, its too soon for that, you are still reeling. Even if you had got back together, you need to go through it, the details, piece it together, it all swirls around and you need to go back over it, like the same process as grieving.. cycle back over before you can let go of it. So dont expect too much of yourself. And you know what? Why not ask him, rant and rave if you like, demand answers, get what you need from him now.. before he shuts down and you no longer have access to him, emotionally.

I am here for you anytime, you have the new number. Thinking of you M. Glad your Mum has come down a notch from furious.

Oh and something else I thought of yesterday and you touch on it here from your C.. all that cr*p about YOU being angry, or b*tchy, or a bad mum for shouting at your kids, or this or that he would level at you.. it was all his guilt and frustration and I bet he doesnt mean a word of it, its how he 'got by' whilst leading a double life, not intentionally I mean, but how he was reminds me now how I was during my EA/Pa.. I was cold, distant, moved around as though there was an exclusion zone around me, didnt want to be touched, didnt reach out, my side of the bed, closed off, less eye contact, scowled at him, tutted, blamed him in my head when only afterwards I realised he was lovely and it was just all me and as a result of their being a 3rd person. Its human nature I think.

So you are none of those things he would shout at you about, and I bet he hates himself right now for trying to drag you down to jusify subconciously his actions.
Love Al xx