It's so easy to say "if this ever happened to me I'd leave" etc.
But life is so much more complicated and leaving isn't always so simple.
Like you OP, my DH had an affair for around be 18 months. I found out for myself that there was certainly an emotional affair going on. But later he confessed to me is was a complete sexual affair.
It was supposed to be a bit of fun for him and ultimately it got way to serious and he broke it off, came home and completely broke down confessing everything.
I'll be honest, it was his breakdown confession that gave me pause for thought and made me take the time to listen to his side. It was so out of character and the remorse was definitely genuine. That's what made me decide to work on repairing our marriage.
Like you, we tried to look long and hard at the root causes. We could put it down to the birth of our first DS. Family dynamic changed, I had a traumatic birth and probably mild PND and, while it's not a great excuse, at a time when we should have sought support in each other we ended up pushing each other away.
Anyway, 3 weeks in is early days and you're going to go up and down at some really random points. You're going to get angry occasionally and occasionally really quite gloomy.
We didn't seek outside councillors in the end but did look into as much advice and forums online as we could.
DH made massive efforts to look at forums for people who had cheated on their partner for advice on where to go from there and how to cut out the OW.
Most importantly we talked endlessly about what happened. We went over things again and again. He talked to me about what was going on in his head (I've never known him so open!) And I talked about what I was feeling.
We just never stopped talking to each other. Trying to understand each other as well as make it clear where we both were in our heads each day.
It's been over a year since he confessed and I won't lie, it's been REALLY hard! We've both worked at this like never before.
It's fair to say that we're not the same couple as we were before, but that doesn't mean we're necessarily worse. We talk MUCH more than we used to. We've discovered different sides to each other and actually laugh more than we did.
If he has to spend any time away with work I still make it clear that I worry and old feelings get stirred up. He does his best to assure me of where he is, who he's with and usually sends me pictures of what he's up to (I know that might sound odd to some but it helps us).
This turned out to be longer than I meant (sorry
).
In short I guess I'm saying that if you are both prepared to work very hard at making it work and there is still love between you then it is possible to forge a new relationship. It will be slightly different but hopefully not always in a worse way.
I'll never forget what happened but I have forgiven.