I need anger management!!!

I don't know why...the Dark Side of me has been active once more. It's my anger...and this time it's killing me!!!

An injustice was done to me some time ago. The thing's over now but I don't know why the feelings of anger, frustration, hatred and vengeance still reside in me despite all efforts that I have tried to reduce it.

I know I have many faults but this anger inside of me refuses to buck down. It's building inside of me, becoming a mega-strong force that sometimes I can't barely control. I lash out at people verbally. The bloodlust cover my eyes and it's as if a demon has possessed me.

Argh....what can I do?