I act like a dick to cope with frustrations I can't express in real life, and because that's just who I am on the Internet. Mostly because of the latter though.
But anyway, depression, at least clinical depression, is hard to "cure", as in, you will never get rid of depression. I myself have been depressed since 2009 (or earlier, perhaps dating back since 2007 or so), and didn't know it until the start of last year. I don't even know why I became depressed (which is all too common for depression, most often you don't even know why you feel the way you feel). I think part is because I felt and still feel like I haven't accomplished anything, that things don't move as fast as I would like. I'm 26 years now, and I still am in the same courses I should have finished three years ago.
But I don't know. I still am not sure why I am still feeling depressed. I one day hope to do the things I love, like writing and stuff, making games, but it always feels like there isn't enough time for that.