Each person requires a different form of communication, a deliverance of speech tailored to their own needs. You can't chat with your mom as you do with your partner, and you cannot talk to your boss the way you speak with your best friend. Knowing how to be a verbal chameleon results in truly effective speech.
Unless there is physical danger, staying in the relationship while you explore and heal your end of the relationship system will serve you well. Once you have healed your end of your relationship system, it will become very clear to you whether or not your relationship has a chance of becoming loving and caring, or whether it is time to move on.
I can't tell if there are more parents getting divorced at mid-life or I'm just paying more attention. Let's face it, we change as we get older. Not just the obvious physical changes, but emotionally, too. As we should. A lot has happened since we fell in love and had dreams of building a future with someone else. By middle age, the distance between the present and the future is a lot shorter than it used to be.