If you choose to hold onto the past, the only  issue is you! The situation is already done and over with. Time eventually moves forward and whatever it is holding you back is no longer the cause of pain, it's you choosing to still be in pain.

Everywhere you stand and everything you touch, hear or smell carries a certain memory to it. If you distance yourself from those things it will be easier to forget the bad that came with them. It is the only way something fades if it is no longer present with you.