We took a Positive Discipline class from Rene Hackney when DS was very young - before we even had a clue that he had ADHD. I found it very helpful and still use what I learned there (DS is now 10).
http://www.parentingplaygroups.com/parentworkshopdescriptions.htm I don't use that technique exclusively. I found 123 Magic helpful as well. The key is to have a repertoire of techniques that you can use.
Have you been to any of the CHADD meetings?
http://www.chadd.org/ I found the lectures helpful in learning about why DS acts the way he does and techniques/approaches to use. One of the key things was getting DH to attend. He was diagnosed with ADHD after DS. DH has challenges removing emotions from situations but at least recognizes behaviors and patterns. Since he's on board with things, it makes my job a lot easier. From going to the CHADD meetings, I learned about other resources that have been very helpful.
Finally, it wasn't until DS started medication at age 6 that we really saw improvements. We delayed medication for a very long time and, in hindsight, we could have used it earlier. Benefits that we saw through appropriate discipline, structure, routine, exercise and diet were just too limited. The lack of self control was having such a negative impact on everyone (as your post painfully reminds me). Everyone, including DS, was a lot happier when we found the right medication. HTH.