In most jurisdictions it is unlawful to fire someone because that person has become disabled by alcohol or addiction to another substance, provided that the person is willing to and does take steps to recover from that illness, just like any other disability. You might consult a lawyer, a priest, an alcoholic counselor and of course your doctor, all of whom are professionally required to keep what ever you tell them confidential.
What is worth more to you- your job or your life? This could well be a new beginning for you. There are all sorts of people, including those on this site, who stand ready to help you. The real danger is not your job. It is what might happen if you continue drinking. So many others have been where you are now and have recovered and are happy. Let them help you and let them share the happiness that can come to you. Every good wish
W.