Sorry for your sitch. Lots you say sounds JUST LIKE MY XW!!!
She said it was too late. She realized OM showed her how much she was missing. The kids would be okay. Maybe we just need some time apart. etcetcetc. blahblahblah.
Sorry to say there is NOTHING you can do. You W needs to figure out what is wrong in HER world. You need to concentrate on YOU.
In my case, I have become a little more sensitive (was pretty sensitive anyway, or so I've come to realize) Funny how now, hell even right after we split, other women thought I was a really swell guy. I couldn't figure it out; XW was telling me what a jerk/a$$hole I was... NOW, I get it that she has major Mommy issues. Her parents both died w/in about 18 months and then her brother almost died, all from Cancer. But it's my fault her life sucks. And my fault OM dumped her!
XW also, like your W, had abandonment issues. Was adopted, never felt Mom loved her unconditionally, "BF" in college wasn't really her BF, more like a good pal... didn't think of her THAT WAY and she wanted him to.
Course NOW her life is great. She got her divorce, got a new dog, found a new man in July, moved in w/ him in Oct, engaged in Nov, new horse, new car, kids can ride the bus home to her house two days a week. Life is GRAND!
I can't wait for her to realize in a year or so that she's just put a bandaid on what she won't face.
So, take care of the kids, don't grovel and worry about the things you CAN control.