Social media platforms are meant to share stuff which is going on in your life and also these platforms offer a lot more things but it’s definitely not necessary to show your sadness on any social media sites.
For a specific reason if you are sharing any kind of sad emotion it is totally fine like last week the whole social media was flooded with the posts of people who showed their sympathy for theSyrian kids who were been killed and were facing brutal bombing. So sharing sadness on these topics is really very genuine as the whole world gets affected by these sort of problems.
But most of the time we see that people post unnecessary things on social media platforms which makes no sense and are idiotic. Collecting sympathy always makes people more coward than making them strong. Sadness and happiness are part of life and instead of sharing your emotions on social media platforms you should try to overcome these emotions.
The only thing I am saying it is not necessary to post such stuff is because apart from few people who are close to you no one cares what you are up to in your life so it’s better to solve in your own possible way.