Feeling down

Well, just got back home from work. Cause as the audit is tomorrow, our office cum the computer office stayed back to rushed finish our stuffs. Actually quite surprise to say, we didn't stay back as late as i have expected!!! So i was quite shocked and happy bout that. As for the whole day today, i duno why, and please dun ask me. I just feel very down like being slipped into a depression!!! I really duno wad had happen to me... SERIOUSLY!!!! Just feel like closing myself up and shut the world outside!!! But it's quite hard. People who know me will say i smile almost everytime, joker.... But they have never really try to see what is my heart... My heart has been seriously hurt for years and i didn't know it too... I think my friends don't know it too.... Or is it because of me being too nosey and stuck up my nose in any of my friends' matters... I just really duno and i cannot seem to find an answer. Has anyone really care bout me??? I duno.... Sign off