So this is the same girl that planned on cheating on you? (And may have for all we know.)
Leave her alone.
Get yourself involved in a new activity - like today, certainly before next Friday. Take a class, join a martial arts group, etc. Go do something you have always wanted to do, and leave her alone. It's a good time to focus on growing as a person.
And I'm sorry that you are in pain. It's part of the unpleasant parts of living, but you will be happy with someone and may even wonder someday what you ever saw in her.