I read her affair texts at the microphone

AITA for exposing my fiance during our own engagement party because I found messages on her phone. My name is Marcus and I am thirty one years old. I have been with Rachel for four years and we got engaged six months ago. Everything seemed perfect. She planned every detail of our engagement party herself. Two hundred guests. Her family flew in from three different states. My parents rented a hall downtown. I was the happiest man alive that night. Then I picked up her phone to take photos for her because mine had died. A message popped up from someone saved as Gym Buddy. The preview said I cannot wait to see you after this fake party is over. My stomach dropped instantly. I opened the messages without thinking twice. What I found made my hands shake. Months of messages. Meetups at hotels. Plans for a future together. This man knew about our wedding date and joked about how Rachel would call it off before the actual ceremony. My mind went blank with rage and humiliation. I looked across the room and saw Rachel laughing with her bridesmaids like nothing was wrong. Two hundred people were celebrating a lie. I walked straight to the microphone at the front of the hall. My hands were still shaking but my voice came out steady. I said I wanted to make a toast before we cut the cake. Rachel smiled and walked toward me thinking this was part of the plan. I looked at her and then looked at the crowd. I read the messages out loud. Word for word. The room went completely silent. Rachel's face turned white as paper. Her mother gasped so loud it echoed. Her father stood up immediately asking what was happening. I told everyone the engagement was over right there on the spot. Rachel tried grabbing the microphone from me but I stepped back. She started crying and screaming that I was crazy and that I misunderstood everything. But the messages were clear as day. There was no misunderstanding possible. Her sister actually admitted later that she suspected something but never said anything because she did not want to ruin the party. My own mother had to physically hold me back from confronting the man who showed up uninvited near the end of the night. Turns out he was a coworker from her office who had been sleeping with her for almost eight months. The venue staff had to escort several guests out because things got so chaotic. Chairs were knocked over. Someone dropped an entire cake trying to leave quickly. My best man told me later it looked like a movie scene, except it was real and it was my life falling apart in front of everyone I loved. Rachel tried calling me every single day for two weeks straight. She sent long messages explaining that it meant nothing and that she panicked because she felt neglected while I was working long hours to save for our wedding. I did not respond to any of it. My family cut ties with her family completely. Mutual friends picked sides almost overnight. Some people said I should have confronted her privately instead of destroying her reputation in front of everyone. Others said she deserved every second of that humiliation for planning a wedding while cheating the entire time. My mother still says she is proud of how calm I stayed while reading those messages. Rachel still insists I ruined her life publicly instead of handling things like an adult. The worst part is finding out the affair started right after I proposed, not before. That detail alone still keeps me up most nights. I keep asking myself if I should have waited until we were alone to confront her. But something in me needed everyone to know the truth immediately, especially since so many people had spent money and time celebrating something completely fake. Now I am left rebuilding my life while dealing with family drama on both sides. So Reddit, tell me honestly, was I wrong for exposing her right there at our own engagement party, or did she bring that humiliation entirely upon herself.