My son is king of emotional outbursts. It is so hard and I am sorry you are having a tough time. When my son starts flipping out, we very calmly, without any kind of judgment in our voice, lead him to his room and say he can throw as big of a fit as he wants as long as ot is in his room. When he rejoins us, we ask if he is feeling better. If he has done something wrong, we discuss ways we can do better next time. I am no expert but that strategy has helped me keep my sanity. You might look into Love and Logic too. They have a lot of great advice that has worked for my son. I used to make him pay me in toys or chores for a ride to school when he was too late to walk. It’s hard to adjust discipline to an adhd child! I am trying to navigate that as well.