Perhaps more then anything...you feel slighted one more time by the religion. One more time it was chosen over respect for you and your feelings. One more time your family has rejected you in some way, however slight, and you are feeling the rage that we all have at one time or another.
Maybe instead of looking at it as a slight to you see it from her eyes. Dealing with the elders/family/daughter and maybe she isn't strong enough to do that right now. A divorce and custody battle are in and of themselves too much. She may view your relationship strong enough and you personally strong enough to be slighted so that she won't have to deal with the issue at hand.
You are strong to her. She is weak. I think about this everytime I have an issue with a sibling. They don't get it and maybe never will but I sure do and I can be there to pick up the pieces in the end.
Just another view...either way I am sorry for how you are being treated and are feeling.