This phrase is typically used to express intense anger, frustration, or rage. It's often used in informal or casual settings, and the repetition of the word "angry" is used to emphasize the intensity of the feeling. It is usually used in an informal setting, in written communication or in social media, it is not an appropriate way to express anger in a professional or serious setting.
"ARGRGHRGHHGR IM SO ANGRY!! IM ANGRY IM SO ANGRY! I just found out I got a parking ticket."
"I can't believe Jetstar canceled my flight! Again! ARGRGHRGHHGR IM SO ANGRY!! IM ANGRY IM SO ANGRY!"