Also, and I can't stress this enough: GAL. You will feel a thousand times better. GAL from the minute you wake up till the minute you pass out from having GAL'd so much.
But don't do it to rub it in her face. Do it for you, and you alone. Be the best you you can be, and make the choice as hard for her as possible.
If she still chooses to go the other way, so be it. You will be a better you, and the next relationship will thrive because of it.