Hi Paddington1,
You raise a really good point. The acting out is behind closed doors from family and friends.
It is difficult to explain the intricacies of your experiences since much of the behaviors are invisible.
Family and friends may of had their own perspective and feelings of your marriage. The key word is YOUR marriage. That being said, a boundary can be that there is no need for you to explain, defend or justify what transpired. She was your spouse. I would suggest saving that for T or letting go of your experiences here with members that were behind said closed doors. Persons from the outside with sound minds won't understand the mental illness and it leaves you looking like your the crazy one explaining.
If your confronted kindly say " I'm sorry. I'm legally seperated and I'm working through this. It's personal and I hope you understand. Thanks."