derived from this crazed-looking :D emoticon combined with this ridiculously disappointed-with-life D: emoticon.
particularly useful when you are talking about a bipolar/manic depressive person, but are far too lazy to spell out either of the above words OR when you're feeling happy and sad about something.
Dan: yeah. she must be D:D
Samantha: HOLY SHIT! i got into the most legit boarding school ever!...but i have to move all the way to Uganda and i won't see you for like 6ish years!
Scarlet: D:D... BALLS!