Even now I'm being an essential shoulder to cry on/someone to talk to for a friend. So why do I feel this need to jump up and down and say "look at me! look at me! I need attention!"?

Asked and answered. You feel uncared for precisely because you are giving attention to someone else and not vice versa. Perfectly valid. Not allowed to feel guilty for giving in to the urge to not be a doormat. Nor for writing about yourself in your own journal, that's what it's here for. We all comment or not of our own free will, too.