I have known many women who have married non-members and are happy. Sure it's lonely and hard work being a "single parent". My dear faithful LDS aunt married a good non-member man. I adore the show New Normal and one of my favorite episodes is when Bryan decides to go back to church and the Father is so cool with him.
Your man is becoming a doctor, and while he's still a resident carving his way into the field, his off days will be few and far between. Expect that you will do the majority of parenting and attend school functions alone. Takes some getting use to. Make an honest effort, and see if you reach the walk-away point.
Another thing to keep in mind: It's a very long, very hard journey to even get to that point of the MD marathon. I remember attending numerous priesthood meetings by myself and wishing dad were next to me. He expects gourmet meals and an immaculate house. But the lies sting some people.
In my experience, life-long member, many Mormons have difficulty thinking outside the box, and putting forth effort to inclue and love. Husband has affair with me, after telling me that he and his wife have grown apart, and we were together for five years. Don't think it's just women married to male physicians who suffer. I gave her a piece of my mind as my home is much happier and healthy now then when I was married to my x. Unless you convert she won't marry you, plain and simple. Unfortunately, it does not get easier, just different. IE в the comment about not having a husband to give priesthood blessings, etc. You'll be richly rewarded. Your crush will watch you closely to see how you interact with these little ones.