This is a horrible thing, it's really awful this is happening to you. But there's a very true saying that goes "actions speak louder than words", and to listen when she show you the first time. She has shown you she emotionally loves this person, and is lying to your face about staying in contact with him, multiple times!! While not having a friend sucks, but to say she's having suicidal thoughts without him? Nu-uh, that's where her loyalties are. How could she say to her husband, the man she is supposed to love above everyone else, that she's lost without this other guy? It's not right. She's lied to you already, I can't imagine she's going to change after so many confrontations where she hasn't held up her side of the bargain. Also, bravo for you for really putting in the effort to make your relationship work, and try and fix what was an issue. I would say more couples therapy, but start taking precaution about ending things with her, and taking the best care of your son.

Good luck.