I actually think that went kind of well. You shared your feelings without being overly emotional and her objections, rationalizations and justifications are amazingly flimsy.
Her reputation has to be rebuilt "starting over" either way, she destroyed her own reputation by having an affair so of course yours is intact.
How exactly is filing for divorce going to stop or otherwise slow down "things getting worse and uglier as time has passed"?
She just doesn't appear to have anything close to solid upon which to hang her hat on. Many way wards have at least a couple of things, like that time you looked at porn (and they call you a porn addict) or that time you shoved them away from you (while they were trying to slap you) as an indication you are just too abusive. Whatever, I FEEL your wife is softening and gaining empathy for you MAYBE as she seems to want to help you through this process (and in so doing come to the realization that you actually care deeply about her more than anyone ever has....which SHE has to realize on her own without you telling her).
Don't fret the divorce action. Sure it's one step closer to being divorced but by the time the divorce actually happens, IF it happens, you'll pretty much be ready for it. Plenty of divorces never finish.
If you were my friend and I was consoling you over a beer I'd encourage you to answer her divorce petition aggressively. I HOPE she files requesting 50/50 custody (don't be shocked if it's not...many attorneys will start out asking for 100% or primary looking to negotiate down to 50/50 from there versus getting caught off guard asking for 50/50 and then realizing the other side is going to counter requesting 100% with supervised visitation. Again...you've already set a pretty laid back cooperative posture which may be OK as a hope for marital reconciliation plan but if you were my buddy, I'd tell you to counter asking for at least primary custody with her getting every other weekend and wednesday nights.
Honestly, she's NOT a very good parent. A good parent doesn't have affairs with married doctors at work jeopardizing their marriages, careers, integrity and families. A good parent doesn't throw away the father of their children to seek out their happiness. A good parent doesn't subject their children to consequences of divorce. A good parent doesn't subject their children to a parade of other men and step fathers needlessly. A good parent doesn't disrespect their vows to God and then, once exposed not fix it and model appropriate behavior for their children how to behave when you've messed up.
Your children are better off raised by you. You are the primary parent concerned about THEIR best interests right now. She hasn't been for awhile. You had them thinking you'd have 100% custody. Your wife had an affair and is (maybe) leaving you...why is she entitled to take away 50% of your custody of the kids??? She's not....
It doesn't hurt your case to simply ask for primary custody. You can hide behind your attorney and say "that's what he/she said I needed to do and I don't want to discuss it". She will have to face herself and look in the mirror and realize that she COULD lose the case and lose even more time with her children and face the inner questions of whether she truly deserves to lose more custody of her kids.
This also depends on the state. You may not want to risk getting contentious like this in a state where you aren't essentially guaranteed at least 50/50 as a dad. Some states are just way to mom leaning to risk alienating a wayward wife that wants to play nice. There is also money considerations and custody cases can get expensive but those are reasons that delaying the divorce, making it a battle, end up leading towards reconciliation. When the addict hits rock bottom, they sometimes climb out of the hole, see the destruction THEY caused all around them and REPENT. If you make this too easy for her...she'll just go with the flow. You can always settle later on back at 50/50 or whatever she's proposing today. if it's fine today...it'll be fine for her later on to.
The internet is 90% complaining and entitlement and I hate it because I deserve better!