Am I The Ahole for ruining my in laws thanksgiving party

Am I the ahole for ruining my in laws thanksgiving party. Hello my name is Jess and I've been married to my husband Marcus for 15 years but I've known him since elementary school. When we first got married his family had asked us to host their annual thanksgiving party as a welcome to the family. Ever since then we host or my sister in law hosts since she recently got married two years back. When Marcus and I first found out we were expecting our first baby we announced it at the thanksgiving party and did it for all four of our kids it was like everyone always expected it once we announced our second pregnancy at thanksgiving. In July my mother in law asked me if she can host the thanksgiving party since she hasn't hosted one in a while I said yes of course. Around August I had found out my husband had been cheating on me with our neighbor from 5 years ago. I’m a stay at home mom and on Tuesday’s I go to the grocery store after dropping off our kids at school, this particular week I decided to go Monday since my oldest daughter had a dentist appointment on Tuesday. I was in our bedroom going through some of my stuff I wanted to donate when I hear the garage door slam, I heard footsteps running towards me so I run and hid. When I hear a giggle from a woman, I rushed up from my hiding spot and cuss both of them out. He had been sneaking her in for god knows how long, and yes for those asking yes we have cameras he had been parking in the garage and sneaking her in that way. After we had talked and made agreements he had asked if I didn’t tell anyone about the affair I said yes and kept my mouth shout I didn’t tell our kids, I was all alone with the most painful thing in my life but what hurt me the most was that he was still seeing her. The annual thanksgiving party finally came, I greeted everyone with the fakes smile and walked to the kitchen to get myself a glass of wine. As we are there I’m sitting with my sister in law and my husband decides to pull me aside and give me rules on how to act like a loving wife in front of his family and before I could say anything his other woman calls. I decided I had enough so once we had said grace I stood up and told his whole family that he was having an affair for half of our marriage and wanted me to act like a loving wife. His whole family sided with me because they don’t tolerate unfaithful people in their household after me and MY kids left the party and left them with their rat of a son. So am I the ahole for ruining my ex in laws party?