Glen, good thoughts here. I appreciated that you picked up on the warning signs early on in the fictional story, as I tried to plant them so people could see the succession of events.
Like you, in college not only were the girls I dated often unhealthy, but so was I. The healthy girls were smart enough to break up with me. But like you said, once I got married to my wife and sw what a relationship could really be, it made me go “oh, so this is what healthy looks like!” However, a caveat. Place two people with their own shortcomings and flaws (we all have them) in a confined space with kids and there will be fights at some point. From there it will be about how you communicate, compromise, and actively listen to one another’s grievances. That alone, will make or break your relationship or marriage.