I've been through it. My thoughts:
Firstly, you're getting excellent advice in the other thread, I would follow it to a T.
Quite a bit of the concepts here are based on the writings of Paul relating to marriage. If you look through basic concepts you'll see many scripture tie-ins.
What you can do is lovingly offer your spouse a roadmap to save the marriage. Forgiveness requires repentance and though your wayward spouse may act like you are being unfair to them, remember you are just asking them to observe basic rules about boundaries/honesty and agree to meet your emotional needs/vice versa. That is exactly the kind of marriage Paul instructs couples to build together.
There's a lot of (sometimes contradictory) theological advice on divorce online, and a fair amount of terrible advice about divorce in Christian books on the subject. I would advise only humility in handling the situation. It's a very tough situation for a believer and many churches don't offer much practical help for divorcees. But...I think divorce can be a tremendous learning opportunity for a betrayed spouse. You've been close to and in the thick of the danger, you understand what it looks like now (MOST couples do not!). And the concepts here can help you avoid it going forward, which is invaluable. His Needs/Her Needs to a betrayed spouse is immediately relevant because you'll recognize so much from experience.
Don't overthink it on what God does or doesn't want, sometimes its impossible for us to know. Keep an eye on the practical things and remember look at your spouse's actions more than their words. You shall know them by their fruits.
God hates divorce but we don't always have the means to prevent it.