How can I work on my sadness and become more with good humor?

Become more humble and less rigid. Accept that things don't come immediately as you expect them to be and embraced imperfection. Laugh about the things you do not like and embraced them with love and not with rigidity.

Stay in the calmness and in the observation and let come and go like a movie, observe from distance and don't analyze but just observe.

Stop analyzing, there is no use and need . It is above your control, you have no control in your life, all is programmed and does its own turns. By having expectations you get rigid and frustrated. Stop having expectations in you just accept the way you are with your good and bad parts and take it easy smile and embrace.

Challenges come to test your humor and teach you to not get sad and rigid, just laugh and embrace. Become less rigid and more calm in your mind.