Me haces falta roughly translates to I need you but this translation doesn't make it justice.
The word need carries a sense of obligation, of something important and essential.
Hacer falta expresses a melancholy hard to describe. It speaks of loving someone and letting them go while aching for their absence.
It's a rushed kiss at the airport, a bittersweet memory of times far gone.
It's embracing my mother on every trip back home and realizing how much smaller she is now.
It is our yearly goodbye at the international bridge and her hand wiping away my tears.