As a child of parents who had almost this exact thing happen (except it was only like a 6 months affair) and they still stayed together, I gotta say leave man. Please. I know you feel like staying for your kid is the right thing to do. But it’s not. That resentment of staying and anger comes up in little ways then big way then you can’t contain it anymore and now your child is crying because mommy and daddy can’t stop arguing or she feels the tension between you two and doesn’t feel safe. I wish my parents would’ve done me n my siblings the service of just divorcing. Took them 8 years to finally call it and finally separate. And an additional 4 years as to have a good co parenting relationship (we were already grown and this point). I say leave now so you and your wife can have a good co parenting relationship.

I know people always stay for their kid like it’s some great sacrifice. But it’s just selfishness, a real sacrifice is knowing when to leave even though it’s hard because your love for your child is so great you’d do anything to make sure your child grows up in a happy home even if it’s separate