Rehab is a good idea. I the meantime you can walk into any AA meeting any time you like. Thousands to choose from in London.
You can get sober. You can make your life manageable again. You can learn to be happy and comfortable in sobriety. And you can clear away the wreckage of your active alcoholic period. All by staying sober for one minute, one hour, one day at a time. Acceptance and willingness will stand you in better stead in this battle than willpower or 'fighting it'.
Wishing you all the best for your sobriety and recovery. BB