Q&A What Kind of Professional Help Should I Seek?

My question is about double betrayal and the aftermath of trauma that follows. My wife of over 20 years started having an affair; physical, emotional, and sexual. I discovered the affair when I found detailed letters. That was enough damage to last a lifetime. The affair partner was my best friend of 34 years. My wife has only prolonged all healing by withholding everything. We had to separate after a few months, but a year later we decided to try EMS Online. I believe she is trying to finally be honest. I needed my wife and I needed my best friend to lean on at the time due to a tragic death at my work I witnessed and walking away from my career. Then my father suddenly past way. In short should I believe the affair is over? Should I stay with my wife? What kind of professional help should I seek?