Psychologist Anna Heal

I'm a 47-year-old man who has been retired from the military for five years. During my service I developed a strict daily routine that kept me focused and disciplined. After retirement I felt lost and started drinking heavily each evening to cope with the sudden lack of structure. My habit started as just a beer or two but now I consume a full bottle of whiskey every night. I've hidden this from my wife and children for three years but last week my wife found my stash in the garage. She is devastated and threatened to leave me if I don't get help. I feel immense shame and guilt. I know I need to stop but I'm terrified of withdrawal symptoms and the emptiness I might feel without alcohol. My question is: What are the first practical steps I can take to break this longstanding alcohol habit that I've used for stress relief since retiring? I'm ready to change but I don't know where to begin.