Hi OP, sorry you’re going through such an awful time -
lots of us have been there, done that and come out the other side happier than before, so please don’t despair.
Perhaps question why it is you feel like you should give him another chance - because he’s begging, because you don’t want to be the one to properly end the relationship, because of the DC? Whatever the motivation, take your time and think it through. None of this now is about him and what he wants. He’s proven to be a liar, cheat and selfish manipulator - he’s literally not someone you recognise as the person you thought you married. This is about your emotional survival and mental health. If your gut is telling you that it’s over, then there’s a real reason for that!
Don’t get sucked into the sunk costs fallacy. Yes, you’ve spent 20 years with this man, but that doesn’t mean you’re obligated to spend another 2/3/5/10 whatever, flogging a dead horse. For me, once the trust was broken then the marriage was over. If someone repeatedly lies and essentially pisses all over a marriage, then there’s no point in trying to salvage what’s clearly unsalvageable.
I read a bit of a cheesy thing but it rang true for me “Trust is like a glass bottle - once it’s broken you can’t just put it back together and fill it back up”.
I couldn’t even contemplate trying to ’move on’ with my ex, once I discovered his deceit and betrayal he disgusted me and made my skin crawl. But, some people do stay together and forgive (although I’m sure they never forget).
From everything I’ve read it actually seems like divorcing is the easiest option, however difficult that is, because in a couple of years it’s done and you’ve moved on to a new
life with a new ‘normal’ (and hopefully feel much happier). Staying together looks like a really, really hard
slog where both parties have to put in an awful lot of work. And then it can still come back to bite you on the arse years and years later. Only you can decide if it’a worth the time, effort and emotional trauma of trying to rebuild your
marriage to this man - and it’s not something you can just forgive and move on from, he has to be willing to give his all to fixing and rebuilding the very foundations of your life together.
I wouldn’t bother, to be honest. Good luck