AA/NA works for those who aren't really addicted, and just need something else to do to keep their minds off of whatever they stopped doing. As a son of someone who went to AA, I've seen it not work at all. Addiction it was, and AA could not help it. Its all up to you now, you have one relapse and its almost guaranteed you will be relapsing the rest of your life.
For the heroin, you should go to NA (Narcotics Anonymous) - you can become acquainted with people who have walked your walk and could probably help you out better than the people who attend AA.
Once you get over the physical withdrawals, find something that occupies all of your time when you aren't at work. Whatever you use to do while on something won't work - cuz you'll only think about how it was when you were all smacked up.
Fly a kite, join the FDBs and be the meat for a MiniD/SOB sandwich with some Animal on the side, or just do volunteer work somewhere, or whatever. Just keep yourself occupied physically and mentally.
-SW