I am sorry about the dog, your children must be very upset.
And yes, I would be pissed off as hell if I were in your situation.
But I do not understand why you can't tell him that you would prefer he didn't discuss you and your problems with the OW, especially in front of you, in your home.
There are ways to do things in a calm and mature way without sounding like the psycho bitch from hell!
You are not a loser. She is, he is but not you!
Sending hugs
((((((((hugs)))))))))
There can be no testimony without a test. I am praying to go through this test and come out the other end with a new and better marriage then before.