My 11yr old grandson was dx'ed with IED when he was in the first grade.
This is a wonderful kid who can be laughing and playing one minute, on top of the world and the next moment he is so angry he is throwing furniture, kicking teachers, spitting, screaming at the top of his lungs, swearing (he never swears normally), hitting peers or teachers. It's really scary to see him go into this. He has very little, if any control over it. When it has passed, he has little memory of being in that space and it scares him and he's so sorry that he could actually be this way. When he is there, there is no reasoning with him. He cannot hear anyone except to be nasty and spiteful back to the person talking to him. It breaks my heart!
I do hope you can find some answers to your anger issues NF. This sounds like a good start for you!
Wishing you well,
sabby