It could just be extremely lucky that he doesn't have internal organ damage yet.
But yes, when you stop to think about everything alcohol does to a body, it's scary. It's no wonder your husband feels so ill, going through withdrawals every few days. If he's going to detox, he needs to go to a treatment center. As was already mentioned, he could have seizures or other serious health episodes, but you know this -- I'm glad you're doing some reading. The more you learn, the better.