When a thing has served its purpose, it will go away. If you try to hold on to something that has already fulfilled its purpose in your life, you are going to hurt yourself. If holding on is disturbing your piece of mind, it makes sense to let go. Surrender all attachments to people and things that you have been struggling to hold on to.
Don't be stressed over something in the past, cause there is nothing you can do to change it. Focus on your present and create your future.
(Source: unknown)