*hugs* Im sorry babe
It hurts and most of us have all been there. Life is about lessons and this is one of them. Have a good cry (us women are such emotional creatures) and then pick yourself up and move on with your life.
Focus on yourself, have a girls night out go watch Sex & the City!
Get your hair done and come into work smoking hot and don't show you are hurt.
Read "Why Men Love Bitches" and "Why Men Marry Bitches" they are an awesome pick me uppper and throw in "You're Not That Into Him Either"
Reading takes your mind off the hurt
Go for a jog, go clubbing, do some retail therapy... keep busy to keep your mind off him. Relationships are habits and it is difficult to get over a habit but time will heal all wounds