How can you fix a broken heart?
You can't fix a broken heart. That's not a useful answer, I
know. A broken heart will heal itself. It is painful. One can
prolong or shorten the pain's duration and intensity. Obsessing
over the loss prolongs it, occupying your mind with other things
shortens it. Analogy; if one has a cut on one's hand, picking at
it, disturbing the flesh increases the pain and prolongs the
healing process. Covering the wound and occupying yourself with
other things will let the wound heal more quickly and with the
minimal amount of pain. It still takes time though.
Advice: Acknowledge that you're in pain, allow yourself to feel
the pain. Grieve the loss, but don't replay the break-up details.
Make a deal with yourself: allow yourself 20 minutes a day to feel
the loss and no more. Within days you will feel less and less
intensity. Clarity will come, you will see.