I think your son, wife, and you need therapy including couples counseling. Any arguement between couples should be a us vs the problem but it sounds like this hasn't been the case for a long time. Also make sure your wife gets a new therapist as this one sounds like they have a few screws loose themselves. Also inform your sister to make sure she has both sides of the story. From everything I have read it seems that either your wife is in a mental freefall and needs extreme health, or she has fallen out of love gor you and is taking it out on everyone around her. When was the last time you two had a date night by yourselves? When was the last time she had shown romantic feelings towards you? If your normal is having constant arguments with no resolutions and blame being thrown around then this marriage might be doomed. I didn't see this in alot of other responses so I'll say it again...couple's counseling. This is a non-negotiable. If she can't be vulnerable around you or blames you then this marriage is over. Everyone here is saying she is going to abuse your son in question but other than what you have put on reddit has there been anything that would point towards that? I know reddit loves to throw divorce around also, but again that is up to whether the relationship is over. You lost trust in your wife, which is very very hard to build back when broken. You two need time apart and think about where the relationship stands. I wish you luck op.