You are having a really hard time and I feel for you. Maybe you could investigate if there are any triggers in food or the environment that cause his issues, like gluten, cow dairy, food additives …… A food and activity journal can help dicover them and would help any professional that you might consult in the future. Some supplements might settle him and calm the brain like fish oil, flavoured liquid form, and a vitamin B complex (preferably methylated – perhaps Mercola, Seeking Health) plus vitamin B3 on its own can settle when beginning to get agitated. There are Facebook groups for ADHD parents too which would give you support and suggestions. Good luck.