I was with you except the "righteous retribution" part. (I even modded you up before checking that, haha) Depression is such an abused term, seldom used for people with something chemically wrong with them. Some individuals are just terrible at letting things go -- it's always been that way and always will be. I'm one of them.
That said, when I'm wronged, the hatred for those who wronged me does fuel me -- but not for righteous retribution, but to: prove them wrong, show them up, surpass them, surpass their preconceived notions, or otherwise knock them down a couple pegs, socially speaking. Who knows, maybe you meant that when you said "righteous retribution" but you let your passion get the best of your phrasing?
BTW, I can speak about this with a recent passion, and hopefully I'll get a chance to confront the individual but otherwise (be it with choice words or indiscriminate 4 letter words), it's become much about proving this individual wrong. Regardless of what happens, it'll be a lot more therapudic than handing out C-notes to shysters like candy.