Emotional pain is a lie ... though it can feel quite real ... it is a story ... a story one is believing about either a past that is over or the non-existent future.
You will know and begin to see this ... when you stop ... for just a moment and take an honest look around ... there is nothing going on but thoughts in your head and they are not real ... they are stories about some other time and place. You can't have a "story" and be in the Present Moment.
Keep the attention on the Present Moment and not the story and emotional pain disappears.