Should I Have Let Cheating Cousins' Wife Know How I Feel About Her?

My 1st cousin stopped talking to me one and a half years ago. It was encouraged to by his cheating wife. He was having trouble in his marriage. She left him 15 years ago when engaged for a guy she knew when 14. My cousin took her back like an idiot. She ran into another guy from her past recently online. The guy told her how he has more money than her husband-is better in the sack, etc. Was going to go out of town to meet him. Her plans were squashed when my cousin found out about it. My cousin asked me to help him by emailing his wife questions-what she likes about him. She finally answered-wrote me an insulting answer. Said I need to stop being so desperate w/ guys. I was so insulted I emailed her back that being desperate is running off w/ guys she knew when she was 14. lol Also wrote she really doesn't love her husband or she wouldn't have almost run off w/ another guy for the 2nd time. Her and I wrote back and forth insulting emails a dozen times. She deleted me from FB and My Space. I wrote my cousin what I think of her-I was tired of hiding how I really feel about her-how he is her doormat. His 16 year old daughter at the time-18 now told me he called me to cuss me out-I didn't answer the phone. This happened a year and a half ago-he hasn't talked to me since. I reached out in emails and voicemail-no response from him. Finally wrote him I'm done w/ him-he's not worth the effort. His 18 yr. old daughter took my side-said she knew I was telling the truth. They told her I was lying. In fact he stopped talking to his 18 yr. old daughter at the same time he stopped talking to me. They live in the same town-he won't talk to her-or see her. He even texted her recently he doesn't want to see her when she texted him. Since the fallout him and his "wonderful" wife had a baby girl. Heard he's spent a boatload of money on his wife and baby to make his wife happy. His wife wanted a baby girl-he even told me in the past he didn't want any more kids. He's so desperate to make his wife happy he cut it off w/ me and his own daughter. Also cut it off w/ my sister and Dad-'cause I let him know they feel the same way that I do. He is going to end up a very lonely man is his wife leaves-his family won't be there for him. Do you think I did the right thing by letting his wife I know how I felt? I believe I had a right to stand up for myself when she insulted me.