Hey buddy, i got to echoe Sandi here. To confront or not is up to you however its not the end goal. It wont necessarily fix anything and are you ready for the fallout separation or divorce especially if she wont stop seeing OM.

You really have to detach, make a plan, what can life be like for you and son without W. Can you do that no matter how difficult, can you seek happiness for yourself and your son.

one of the things i love right now despite being separated is my S5 and i are closer than ever. I spend my waking hours trying to him and me happy.

You need to prepare yourself. Like Steady9 says, once you are willing to let go things change.

Me31 W31 M11yrs S6yrs
23Mar16-BD
9Apr16-W admitted EA w boss.
27Jun16-W Changed job and promised NC w OM.
14Jul16-Continued contact w OM.Start of Separation.
24May17-Divorced.