Is AUTHOR wrong in the post ? POST : AITA for cutting my best friend off?

Me and my husband were in a clique with many married couples. Our best friends were also our neighbors.
The whole clique is very intimate and two of the couples had swap their partners in bed a few years ago. But I always said, that's not my business.
My best friend married in July and 5 weeks after that day she found out that her husband had cheated on her with two of our girlfriends in the clique (which were also married). He sent dick pics of him, secretly took photos of her naked while she was asleep and sent them to our friends, sexting with these girls and so on. When she found out she was depressed and cut our "friends" off for obviously reasons.
I did my best to help her heal her heart and make her a bit happier. She decided to not break up with her husband, because they have a 7 years old boy and he promised her to never do it again (info: It wasn't the first time he did this..more like the 4th time).
I was not thrilled, when she told me this but as a good friend I told her my opinion and also that I  would be there even when he is a dumbass and she will take him back. She thanked me for my support.
I also cut off our other friends, because on the one hand I wanted to be supportive for my friend and on the other hand these things were morally reprehensible and I don't want to be friends with these peoples.
It was a big thing for me to do so, because I have a social anxiety (I'm afraid to stand up for me and my opinions because I don't want to make anyone angry or hating me) but when I have done this I felt proud for me.

Now my friend have forgive them all and is happy with these false friends and it makes me very angry. I don't want to be friends with these peoples and I think what she does is dumb as fuck and I told her so. They have betrayed her, but a few month after all these things happened everything is okay and I'm sitting here locked out from the clique for being a good friend.
So I decided to cut off with her and looking forward for new friends, since she told me I should not stick my nose in her life and I should be happy that she had forgive them. 

Now she texted me I am a bitch and a bad friend for breaking our relationship, but she doesn't want to hear my arguments and just insults me. I have tried to be friends even she is befriended with the old clique but it cuts my heart of to see what she have done to herself and my work to fix up her heart again. I believe that these friends will hurt her again and she don't want to listen.
My husband couldn't stand her since they met the first time, so he is happy to see that I have broken up with her but I am feeling like I am the asshole for no accepting her decisions. 
	
tl,dr: cut off my best friend for her decisions to forgive people who hurt her months ago 
	
