You mentioned that your DS wakes up a lot during the night. Have you looked into the possiblity of sleep apnea? Waking up a lot at night, snoring, or just seeming like he didn't get as much sleep as he did can be signs of sleep apnea. I have read that a lot of kids with undiagnosed sleep apnea can act as if they have ADHD. Just a thought.
Oh, another thought, too. I read somewhere (I think in those "Your X-Year Old" books) that kids go through cycles of disequilibrium that often coincide roughly with their half birthdays. So, around their birthdays all is going well, they're following rules and routines, they're generally pleasant. And then, wham-o, at around their half-birthday they start questioning all the rules again and they start acting out and pushing limits -- kind of a stretching out period. And then it all normalizes again. I obviously don't know if this is the case with your DS and I'm guessing it can happen at any intervals, but I see this with my kids.
I hope everything returns to a state of equilibrium again and that you have happy days ahead.
