I had to just stop it all together, and sought the support of AA for a few years. If you feel that you may have developed a physical dependency, (like having to drink everyday to avoid the shakes,) I would seek medical advice before attempting to stop or cut down.
How much does one need to drink daily to develop physical dependency? I guess it depends on the person, but still maybe you can give a reference?
I think I am in the same boat (no pun intended) than Ibian... completely functional, almost no effect (except the weight gain), but still an absurdly high amount of daily alcohol consumption since maaaaany years ago. I did switch from whisky+coke to beer and wine since I stopped smoking though. That was easy.
I was married to an alcoholic and the best explanation I found for it was this...
When you drink you're essentially drinking a poison. The first few times your body is like 'WTF?' and you puke and feel miserable the next day. Your body continues to fight it for a while but if you're drinking large amounts of alcohol before you're 25 or so while your body is still developing (the earlier, the worse) your body is like 'ok, I guess this is a thing that is necessary'. So your body begins to adapt. It changes your chemistry so that drinking alcohol is part of what you do, it eventually gets to the point where it is something your body needs.
It is at this point that you are an alcoholic. When you go without alcohol your body starts to crave it, as though you are going without water. If you go too long without it you start to get angry for no reason, you convince yourself that having a drink is ok. Your body needs the alcohol.
I can't say what the way forward is because your body chemistry is already altered. I am not sure if stopping drinking will change it back...if you're much older it may take years. For my wife it just got worse and worse...she eventually passed away partly due to the drinking (and trying to use prescriptions to counter some of the problems brought on by drinking).
Personally I have stopped almost completely. Not because I was addicted but I have realized that I may be rich enough in my old age to be able to afford the life extension treatments that most will not have access to. But I don't want to be old and falling apart when that happens so I'm trying to choose a healthy lifestyle. Alcohol adds nothing positive to your body and for me was always something I used as a crutch to socialize better. But fuck that, I'd rather live for 100s of years than be the life of the party.