but there is one mistake i see a lot on social media - there is this idea that if i just share my feelings, people will care

this is the wrong idea

you have to reframe a bit. is this of interest? have i got anything to share that they might care about?

don't get me wrong - i get egocentric at times - but if you're going to have a moment like that, maybe try to make it interesting - seeing as posting on a social medium is a social activity.