thrill - be 100% sure that your D is going to be final before you send such an email. And even then, I would advise against it. It will not make you feel any better, although you might think it would. Just take the high road- I know that everyone in your shoes is tired of hearing that, but in the end, YOU will come out better for it. Taking the high road is actually for YOU, not the other person.
As for the father figure OM, yes, I am sure it is all part of the MLC and one day, she will wake up from her stupor and say "what was I thinking?" But....that won't really help you either. It never really helps us when the MLC or WAS wakes up from their fog, if the devastation has already come down and the D is done. By then, it doesn't really make a difference to us, just a lingering feeling of "well, I am glad to know I wasn't crazy - THEY were crazy".
Hang in there...I hope you will come out ok in the end.