either something happens that makes you that way, or you do something yourself that makes you feel that way.  if it's the former, and there's a legitimate reason for you to be upset, give yourself ten minutes.  bawl your eyes out, hate on something, fucking jab your foolscap paper with a bloody ballpoint pen.  then walk away.  put yourself in a situation where something will magically happen to make you happy (try to find someone who's holding a FREE HUGS sign, or well, just buy a coffee from a barista and perhaps a second hand book, plonk your tosh down somewhere).  if it's the latter, what specifically are you doing to yourself?  are you surrounding yourself with bad people?  are you reading bad stuff?  are you thinking bad thoughts?  the word bad is strategically used, because of its generalisability, to allow you to find a more appropriate word.  bad is bad is bad.  you may be hanging around people who are sucking your good mojo away.  leave.  you may be reading stuff that makes you hate on yourself.  watch cat videos instead.  don't get upset.  are you thinking bad thoughts?  are you?  if you are, shame on you, pamela ng.  stop them bad thoughts.  there isn't a point to it.  you're one of the luckiest persons on earth.  you've come through so much.  you're loved.  don't latch on to bad thoughts.  think good thoughts.  positive thoughts.  make a list.  make a list to help yourself be better.  don't sulk.  ladies don't sulk.  be happy. 

BE. HAPPY.