I think this quote from the article BJ1 linked to above describes the relationship between drinking and happiness very clearly:
The Freedom Model does not say you need to be happy first and that happiness will then stop you from using substances. It says that you will do what you see as your happiest option and that you have the power to change the way you see things, to cease seeing heavy substance use as your happiest option.
All you had to do initially to get motivated to start using substances was believe it would be worth it. In fact, many people’s early experiences with substance use are painful and involve vomiting, coughing, and other problems and miserable outcomes, yet they persisted because of a belief that they can do it in the right way to acquire happiness. All you need to do to change your substance use is believe it’ll genuinely be worth changing. You need to believe that a change offers you the chance of greater happiness, and you will then persist on this new path if you believe it’s a viable possibility. Building this new preference starts the same way you built the old preference...
...When you use substances heavily, it is because you believe it is the best available option you have for happiness at the time. When you repeatedly do this, it’s probably because you’ve believed that enough to create a preference for heavy substance use that you no longer think about much – that is, you don’t consciously think “this is my best available option for happiness right now”, but it’s just what you implicitly believe and act on without much thought anymore. As long as the beliefs that underlie that preference remain unexamined and unchanged, it will stay in place, and you will crave, want, or desire heavy substance use, even while you know it’s costing you a lot. If you examine your preference, you can change it, by coming to believe that a reduction or quit will bring you more happiness than heavy substance use. You don’t have to believe it’s going to be utter bliss or joy, you just need to believe it’s the happier option. That could mean, on a happiness scale of 1 to 10, that heavy use rates as a 1 in your mind, but abstinence rates as a 2. It doesn’t mean abstinence solves all your problems or results in total joy – just that you like it better than heavy use. The Freedom Model for Addictions is designed to help people sort through this issue, and really come face to face with the happiness potential of all their options. If you don’t believe a change is worth making, you probably won’t follow through on it.