As far as her swearing on your son's life, I don't buy it. My wife would have said anything rather than to admit that there was someone else. So I'd move forward assuming she's at least in some stage of another EA.
So did mine. At bomb day, mine said “I’ll swear on our kids’ lives I’ve always been faithful and there’s never been anyone else. You’ve probably been having an affair, and that’s why we’ve grown apart.” - she said all this, while actively attending church, while engaged in an affair with a guy from S’s soccer team.
She’s lying to you.
At this point, I think DBing is your second priority.
Your first priority is actually getting some IC to determine if you want to save this. The fact that you’ve thought about divorce from time to time is a huge red flag. While it’s admiral to stay together for your son, if the marriage remains crap or marginal, he’s actually better off with two happy and separated parents.
I wouldn’t do marriage counselling. Work out what you want before you even consider it.
