When you have no "get-out-of-jail free" card, you tend to work harder (and smarter) to make it better.
We Catholics should also ponder our de facto divorces in the forms of annulments.
If our Church is issuing annulments left and right, then we are doing something very wrong. Annulments should be exceptional, not routine.
I knew a canonist who said that problem is not just that marriages fail, it's that priests allow marriages that never should have happened in the first place. They don't take the time to investigate whether all the elements of a sacramental marriage are present.
I'll confess that I have been mad enough at my husband to want to leave (and to be fair, he's probably thought of it, too). Then I sat down and thought about the cost-- what it would do to my children. I said to myself: I'm not going to screw up my kids' lives for MY PROBLEM.
When you realize what's at stake, that it's not just about YOU, then you're a lot more conciliatory. Just because you're unhappy now doesn't mean you'll be unhappy 6 months or a year down the line.
And reading a lot of Dr. Phil helped. When it comes to making a marriage happy, the most important person in the marriage is YOU.