She has out and out said that she hopes to find another man to replace me "that the kids can call daddy".

This comment that you said she made absolutely infuriates me. she's threatening to punish the kids for something that is between you and herself. She can't use the children against you, genetics is fairly set in stone. Regardless of the fact that you and her weren't able to make things work in the relationship, those are and will always be your children and its extremely selfish and unrealistic (and intentionally hurtful) for her to believe otherwise, regardless of how much she's hurting. And as far as letting go of stereotypical ideas of what the "pristine life" should be, a lot of traditional stereotypes of the white picket fence and the happily ever after are just that. Stereotypes, images, and what we're raised to believe is the perfect life. Ultimately, they're highly unrealistic and it's amazing what goes on behind closed doors. Your marriage isn't the only one failing, every couple has their ups and downs, beginnings (and unfortunately sometimes ends). We have to accept that life can really suck sometimes, but not always and for that you can never lose hope. Every time one door closes, a window opens. You just have to find it