That can be really hard. Sadness is a normal emotion, sometimes you just have to let it run its course.
How to be happy when you feel sad?
It depends what caused the sadness.
Usually you need to let the time & it's phase pass on it's own.
But you can try thinking about good memories you've had. The brighter sides of anything that caused the sadness. Try to spread out positiveness over your mind & heart. Talk to someone that you know would change your mood & will make you smile & happier overall. Watch a funny movie, listen to your favorite musics if you have one. Try to do things that you really love doing them.
Hopefully you feel better soon.
Change of scenery. Take a walk. Spend time with people you love.
Talk to friends or a trusted family member. A therapist if one is needed.
Help someone. It'll take your mind off of your troubles, give you perspective, and give you a good feeling.
Listen to music and write about how you feel in a journal.
These are things that really help me during difficult times.
Reaching out to help someone else can be a spirit lifter. It gets the focus off of our own problems .... Which are sometimes not as bad as we imagine them to be. There are usually plenty of reasons to be grateful. I hope you'll find your joy again soon.
There is nothing wrong with feeling sad. It is part of life. You need to let it run its course. It is what makes you appreciate the good times. With that said if you have a pet, snuggle up! Pets are good listeners too.
You are the source of your happiness and
your sadness. Ever try being sad when your happy?
You can't. You are steering the ship called you.
Don't run a ground.