A breakup is not the end of the world. However a relationship ending is very similar to someone dear being snatched away. What you are going through is the grief process. It will take some time to be fine but time will definitely heal.
Next Steps
Keep talking to someone you feel understands you. If there is no one like that meet a Psychologist.
Health Tips
Keep the relationship space vacant for some time at least. Beware of rebound relationships.