Good decisions made my friends hate me.

I don't know why this hurts me but, my small group of friends stop talking to me because one of my now ex friend cheated on he's wife with a 16 year old girl after he spoke to me about it I told him I didn't respect or like what he did. I said that I don't want to can continue to be friends with him I guess that didn't sit well with him because after that he had a talk with our friend group. I have no idea what he told them but none of them will speak to me it's been a month since this happened and for some reason I feel like I did something wrong.

I feel really lonely and felt like I needed to tell someone.