Other day I was reading a post on Quora. There was a technique or you can call it rule 5-5-5.

If you are sad or something bad happens to you but you want to get rid of that.Just think about it does it matter to you for the next five seconds. Then think about it does it matter for the next five minutes and then for the next five years. I am sure all of us will get all the answers.

Condition is that after that you will not think about it anymore. I have started trying it and it is quite effective.