Hi and sorry you had to come here, but welcome. Can you tell us a little more history about your son? Did he have a difficult time in his very early years? Any loss of caregivers? Any abuse? Was he ever intensively tested by, say, a neuropsychologist? Is your husband his father? If not, where is his father?
To me, and I'm just a mom, it sounds like more is going on than just ADHD.
Does he ever get violent? Does he know how to make friends and keep them? Any obsessive interests?
Is he maybe doing drugs?