I know where you are coming from...my son has the same issues. He was diagnosed ADHD and ODD beginning at age 5 1/2. Because of anger and aggression issues, he recently was diagnosed Bipolar as well.
I would recommend a Neuro-psychiatric evaluation like Lisa said. When my son had the Neuro-psychiatric it confirmed the mood disorder diagnosis.
Please know you are not alone. I am a teacher, therefore a full-time stay at home mom during the summer. You are right, it is exhausting!