Sweating is a classic sign of withdrawal. When people become physically dependent on substances like alcohol and opiate drugs (heroin, morphine, Oxycontin and others) and then stop taking these substances, the body takes a while to recalibrate to its normal operation. And that's when withdrawal symptoms, like excess sweating, kick in.
It's ironic how drinking alcohol makes you sweat, but then stopping your alcohol consumption after becoming dependent on it can make the sweating even worse. Never fear. While incredibly uncomfortable, it's temporary. Some medications are available to help, but the symptoms will eventually go away on their own. Depending on the severity of the withdrawal, it can take weeks for symptoms to subside.