The best way to tackle a large problem is to break it down into small, manageable ones. What about your life makes you miserable? Take a pencil and and piece of paper and write down each thing that is making you unhappy. Then, take one step at a time to alleviate those issues.
Just quitting drinking doesn't change the rest of our lives. It just gives us the opportunity to face our challenges with a clear head. You can do this. We're all on your side and we're here to support you.