Write about how you feel at that moment, be honest to yourself as much as possible. It's okay if you want to destroy the content later. This practice will actually bring more clarity of mind and will definitely keep you at peace.
Talk to someone who's nowhere related to the issue you are facing and who can be more of a good listener. It's okay if they can’t advice you, actually it's better if they don't.
Watch as much of humor related shows as possible, you can even attend some stand up comedy shows. If that’s not affordable you can just follow few comedians on social media platforms and trust me they will promise to keep you happy forever in every possible way. Just a piece of personal experience.
Talk to yourself and explain things that didn’t work for you, also look for an explanation how it could be better in future. Trust me no one can advice you better than yourself and also there's no fear of being judged.
Read books that can motivate you and keep you alive. Anything that can keep your spirits high.
Always try engaging yourself in creative activities. It can be anything that requires the attention of all your senses not only physically but also mentally.
Over think but only about something good and fascinating and not anything that depresses you or lowers your self esteem.
Be with more of positive people as much as possible. If that’s difficult then try turning their negativity into something positive.
Avoid regretting as much as possible, I used to regret a lot before but with time I have mastered the game of avoidance. The regret stays with you forever so it's better not to keep one.