“How do you stop loving someone when they do not love you back?”
Stopping love is impossible. We do not chose who we love, it just grows. Nor do we have a choice on who loves us back. You can love from afar but that too is painful.
Sadly the only cure is time and even that is not a cure. Time eases the pain and does not stop you loving them.
Keeping yourself occupied will help time pass and can temporarily even ease the pain.
May time pass quickly for you.