According to most drug and alcohol rehab websites it is most defiantly NOT safe to just stop drinking if your body is used to heavy drinking. The reasons being, it can bring on a fit, seizure or even worse and in some cases it can be fatal. My advice would be, go and seek medical help either through your doctor or a rehab centre. It costs you nothing for advice from any centre, or call the addiction helpline.
www.addictionHelpline.co.uk Saying that , I have just noticed the Addiction Helplines phone number is at the top of the page here. Good luck.