Totally understand this, used to feel exactly the same.
If I didn't challenge, I felt like I was condoning it. I wanted her, and the whole world, to know that it was just wrong. I wanted recognition of how wrong it was, and it drove me mad that there didn't seem to be any. I also used to spend huge amounts of time carefully planning my speeches. If I could just find the right angle, the most incisive words, then I might have a chance of getting her to see sense.
Those feelings are so powerful, but sadly, acting on them doesn't help. I never felt better afterwards. All of that anger and frustration needs to come out, but when I hurled it at her, it bounced right back at me and reminded me how utterly powerless I was.
The only thing that did help was writing it all out, or talking to my partner (who is calm), just to get the feelings out. I would say 'it's wrong, I hate it' and it really helped to just have someone else agree.