cringing at vulnerability

i find that a lot of the times, i regret opening up to people. i don't mean in the sense that the things i tell get out to others, but when i've recuperated from whatever emotions that were once affecting me, i feel stupid for having made such a big deal out of things that no longer seem important. especially when i'm sad, i often think differently and say things that are completely desperate and insecure. then later, though i may have meant those things at the time, i wonder how i could have shared my feelings to that extent. i always tend to have thoughts the day after along the lines of, why couldn't i have just held that in for a little longer? why'd i have to let myself become so vulnerable? yet at the moment, vulnerability feels pretty satisfying.

i think it has to do with people's reactions to things after the fact. of course if a friend's feeling down, everyone will crowd around and console them for the time being. however if that person later on starts laughing at him/herself, then others will usually join in and agree that he/she overreacted. and when those types of situations come up is when i start to regret opening up.