Same as alix.ehrhardt, our son, turning 8 now, was diagnosed with Oppositional Defiance Disorder, and prescribed risperidone. It has helped a lot so far! The extreme anger and reactions to situations that triggers negative response has reduced in occurrence a lot. I now feel I can handle it better when it comes, since is does not feel like ALL THE TIME anymore. If it is ODD, and not treated it can get worse, the fact that you land in a shouting match with him on a regular basis only feeds the ODD. I landed in that trap too many times to count. Sometimes you are already stressed or the rope of your patience has been chewed on by the dog and before you know it, you are losing the match as well!
I also find that sometimes it is better to ignore the situation and send him to his room(even though the neighbors might think he is being turtured), I chat about the extreme behavior afterwards and ask him what he thinks a better reaction would have been…. This I manage on my good days!
Hang in there, you are not alone!