It a lot like grieving, it takes time to mend a broken heart. You are in control of what you think about. Don't allow negative broken relationship images and ideas fill your head. Push them out when you become aware of them. Eventually they will gradually decrease to enter and you can move on.
Good luck

It's like a cold, there is no cure, it just has to run it's course.
After I've cried and rehearsed in my mind what brought it about I like to talk about it preferably with the individual that caused it. I am a peacemaker so it's easy for me to want to discuss the events that led up to the pain with all involved. I believe talking it out is the best method to heal a broken heart. If by chance there is not an opportunity to talk than I would write out what I am feeling and I would deal with my emotions as they arise, not suppress them thereby empting my heart and mind of all negative reminders of the pain.
The wonderful thing about a broken heart is you have the final say as to how long the pain will stay with you.