What happens next?

How to ignore your feelings for someone that doesn't feel the same
Allow yourself to feel upset.
While you may be tempted to push your feelings down and pretend they don't exist, this is only a temporary solution. Feelings don't just " go away " if you ignore them--they come out in other, usually destructive ways.
Give yourself the time and space to express your sadness. Cry, punch a pillow, sit in your car and scream if you think it will release some of the negativity.