Help-My Wife Says She Isn't Happy.

So after 13 years and 2 kids my wife comes to me the other day and
says she "isn't happy anymore". She claims there is no one else but
that we have nothing in common anymore. I convinced her to try seeing
a councelor but now all I can think about is that I might be getting
a
divorce. I don't know how to act, what to say, or what to do in my
own
house anymore.

Any advice folks? How the hell can you just make someone magically
happy? I'd almost feel better if she said she met someone else. At
least that's something I can wrap my head around....