This should serve as a lesson to ALL, married or not. It all starts off nice, with champagne toasts, boquets and rice flying everywhere, but we all know that this bliss doesn't last forever. All of the "little" disagreements add up over time, and you either deal w/them and accept this as normal, or things go even further south. Even all you "happily married" guys know it's not all 'banging & kissing'!
I was married once, went through this w/ 2 kids & though I won't go into detail, it all worked out very well. You have to experience this to know how hard it is, so I do feel for you, man.
I have been with my girlfriend for 8 years now, we maintain separate households, and though I 'never say never', we're fine right now! BTW: my 2 sons live w/ me full time, and life w/ a 16yr old & 19yr old, both now into cars (and both sport some badass rides) could not be better! Who knew that going through the toughest experience of my life would end up w/ me having a VERY tight bond w/ both my sons, as I focussed on them, and not their mother. And her....it's correct that they will always be around, and she's around. Always nod my head when I see her...her main purpose, in the end, was to give birth to my sons...the love part, I got from them, and for the past 8 yrs...my "new" lady.
Just my 2 cents in all this: Keep a cool head, and if you move on w/ another lady, or start dating, keep it on the down-low & don't flaunt it, as much as you want to. Sounds like a missed opportunity to 'get back at her', but it will end up hurting you more than you might expect (& you're already in a heap of .... now).