12 years isn't exactly "going the distance."

Considering all those things you mentioned that never even happened, it doesn't really sound like the relationship is damaged beyond recognition, I mean really. It sounds like far worse could be the case.

There are always times in a relationship when we feel like we fall out of love. That's why love is more than is what is required to make a relationship last.

Unfortunately, in western society in particular, people have this unrealistic fantasy, movie-version idea about what marriage is supposed to look like, and all that lovey-dovey crap. But real love involves doing, and not just feeling...it involves sticking though the shit, even when we feel like we want to strangle a person. It's getting through the hard times, because ANYBODY can get through the easy times. It's being there even when we don't want to be. And your character will grow all the more just for doing it.

Imagine if a real tragedy happened to one of you, like an accident or a disfigurement, or if one of you got sick...would you abandon the relationship as a result? This is no different, in that you are both being confronted with a crisis in the relationship. And one, or both of you, are sick (emotionally, relationally, etc.) and it's affecting your relationship with each other.

There's obviously a huge communication problem in your relationship. You may want to consider couples counseling to at least hash some of these things out.