I would never give up on him because he got nobody else.
If I were a Good Doctor's Wife I'd be loving and reassuring and tell him that everything is going to be ok.
Even Mormon girls who marry non-Mormons want great dads for their kids, and they are oriented to having kids, sometimes many kids. It seems she'll expect you to become Mormon.
I've been the main parent for 30 years. The religious differences between you two are a deal-breaking fault.
But I do believe in modern prophets and that God gives no commandment that is not for our own happiness. Her experience may or may not be typical, but it is something to consider.
This means no swearing, loud talking, or making offensive jokes.
A good place to go is to a museum, hiking, or to a park.