I think you and your husband are from a different culture background. So, don't use your background to understand your husband and your husband's family to fight this "war".
Good that you did not slap any one's face. Otherwise, it could be a crime from your husband's culture.
From the culture I am living in now, slap on someone's face is a crime.
Your parents really made a bad move by opening the door of your husband's home (at that time, you guys were separating) according to your husband's family culture.
I married to a husband from a different culture. Giving my home key to my parents would make my husband very mad. I never do that. Even my Mother in Law contributed the down payment for my parents' home, my husband did not give the home key to his Mother.
Your husband's marriage value and family value are different than yours. .......
Your husband might found himself not capable to live in your family culture.
I can understand why your husband's family think your husband have not done anything wrong according to their family culture.
It is no one's fault here. Not you, nor your husband according to your own different cultures. May all of you have minimum hurts after all.