The other thing is...
The people who run the local detox program are almost all (perhaps all) people who have had substance abuse problems themselves. You do not need to explain anything to them or make any excuses to them. BS does you no good.
This is in contrast to most of the professionals I have dealt with about my alcohol problem.
After graduation from the detox program, I started seeing a psychiatrist. She was a complete waste of time. I probably spent $5000 on her. She knew the terms, but she was useless.
This was not true of the detox program.
The thing is, you cannot get cured of a problem in a week. I stayed clean for several months, but then something trivial went wrong and I was back in the bag that afternoon.
Addictions are vicious things. Monsters.