Grey's Anatomy, Season 3 Episode 6.
Nancy to Derek Shepard:

You're running in circles...
Do you remember the last time you were single?
You've never been single, ever.
You're fine, but you're not happy.
You're never gonna be happy until you get some Space.
Just get away... Away,...
Until you figure out what you want.

I'm sure some girls I used to know can use that advice too.