There are many things you can do, and some will work for certain pople and others will not. Speaking to friends, for instance, does not work for me. I spent a weekend with my friends at a music festival and got really sad and angry for the last two days. What I needed was a private room and time for myself. For others, being alone makes them sad, and they need to be with friends to cheer up. I generally find that treating yourself to things you enjoy helps a little, and also talking to people online who you do not know personally about your issues helps.

Go outside and take a walk. Nature is refreshing. Then, find the reason for your unhappiness and fix it.

to speak with friends is helpful.