I know the thought of being without her feels like your heart is being ripped out. I promise you, you'll get through it like so many others before you. Right now you need to work on building friendships and outside relationships so that your entire focus is not on that person (I understand because that's how my life has been for far too long).
Others might recommend marital counselling, but in my humble opinion, that's just prolonging the inevitable. If you love her, you'll let her go and be happy. It might take that much for her to realize that she loves you. Or, you might realize that you can be happy on your own. Don't drag out a failed relationship (again.. speaking from experience).