Most Helpful Girl
If anything is endangering your relationship, it is how big of a freaking deal your making out of this. I understand your fear of her leaving, because honestly it could potentially mean that she's on the verge of ending it.
But it could also mean she just needs her own space. This is a normal desire for a lot of people. In fact in some parts of the world, happily married people live in different houses! It may not be the most financially savvy idea, but it's a lot easier to get along with a person whom you don't spend every moment of your life with. Some people need space. My best friend and I love each other, but during the summer when we spend up to two weeks living and breathing each other in the same house, we can't stand each other.
My advice is to just not worry about it right now. Let it happen. Because if you're constantly proding at the subject, that will drive her away more. You don't have control over wether or not she leaves, so you might as well be along for the ride.1