If he is able to quit drinking under the care of a doctor and/or in a rehab hospital the risk of complications or death or decrease immensely. Certain temporary meds can be prescribed that will help with the PAWS (post alcohol withdrawals)...quitting drinking cold turkey poses risks and the possibility of death for any alcoholic. It will be tough but well worth it. In the meantime you need all of the support you can get. SR is a great first step.
Have you looked into attending an ALON or other support meeting? You will meet and encounter many others going through the same type of situation.