In answer to your specific question, there are at least two regular posters on here for whom this has happened. As I recall, neither of them are still with their Hs, although both made superhuman efforts to get past this, but neither "man" had the necessary character and emotional intelligence to work through the issues and take responsibility. Hopefully they will be along at some point to tell you their stories.
I agree with the others here and I am writing from the perspective of a woman whose H had an affair. Both the OW and your H are to blame for this situation, but in my experience, you can only ever get past a situation like this when your H takes full responsibility for his actions. You seem in denial about his role in this and he is hiding beneath your skirts at the moment, which in your shoes would make me lose even more respect for him.
I would be very wary of only getting help from church folk too - I think your H needs to do the most enormous amount of work on himself - and that means solo counselling with a trained professional and facing up to the consequences - before you can ever be sure that he has changed as a person.
I'd query yur motivation for having another child too and wonder whether you're in a bit of denial about why you decided to do this. If any of it is rooted in competition with the OW, it needs to be acknowledged.
Your H cannot hide away from the mess he has created and expecting you to view photos that must wound you, is actually cruel.
It doesn't matter either who pursued whom at the start of an affair. If it was her, he could have said "no" and if it was him (as seems likely given what she's said) then he needs to admit that. She didn't trick him into a pregnancy either and he risked not only that, but also your sexual health. I hope he and you have had a STI test; it's a must as she won't have been tested in pregnancy unless she specifically requested it, as you no doubt know from your recent experience.
Please don't bargain this away and infantilise him as a poor man who got tempted by a wanton woman. And stop clearing up his mess for him. He's a father to this child, whether he likes it or not. He needs to provide for that child at the very least and acknowledge that he's reduced your financial options for the next 18 years at least and reduced what is available for your own family.