Holding on or Letting go?

Which is more difficult? Which is more easier? To hold on or to let him go? I saw this topic in Soompi and the girl need advices about this guy she loves but love someone else.. Complicated, i say. Well, for me.. she should let go. Letting go is much more painful like holding on but you know? Time passes and it heals.. Okay, if you hold on you will be hurting AGAIN AND AGAIN, you always feel the pain that you will never loved back. IT HURTS. But when you let him go, AGAIN, Time heals. :)))