First, congrats on recognizing there was a problem and doing something about it. Many, many addicts don’t get that far.
Second, on a practical note, as others have said, your body is just going through a change you have to ride out. Remind yourself that not only your brain chemistry but your entire system has (a) been abused for 20 years and (b) is learning how to function without the abuse. The situation is temporary. You’re casting about for ways to cope, that’s OK – it’s a learning process for you and your body. The important thing to remember is that if one method doesn’t work after a fair shot, try something else. There’s always something else to try, but give everything you try a fair shot. Set up your body and brain for success: Eat well – good nutritious food on a regular schedule. Try not to sub junk food for the booze, but if that’s the majik key to get you through the day, then that’s what gets you through the day. Obviously caffeine is causing problems, or exacerbating existing problems. It is a drug, after all. Green tea has it unless it is decaf. You say you don’t like diet soft drinks, but you might try caffeine free Diet Dr. Pepper and Sprite Zero. Both taste very close to the real thing. Or, decaf anything else you like – coffee, tea, hot or cold.
I’m not an alcoholic or a smoker or a drug abuser, but I AM a compulsive overeater and my brain is wired like any other addict and I share many traits and quirks and thought processes with other addicts. My best friend is a recovering (for the second time) alcoholic. Not surprisingly, some of the survival strategies are the same. Yes, understanding WHY is important in the long run, and going down those roads of self-discovery can help you. Today, right this minute, though, what’s important is NOT drinking. That’s all that matters. NOT drinking. And, when a relapse occurs, the important thing is STOPPING and then NOT DRINKING. One day, one hour, one minute at a time. What are you doing right now, right this second? NOT DRINKING. For a long time, that will feel like that’s all you are capable of doing. That’s OK. What’s important is that you are NOT DRINKING. What strategies will you employ to make sure that happens? Only you can discover them, but they will be similar to the strategies that many other addicts use. That’s why most people are encouraging you to find some group support. It may take time for you to find the group that works best for you, whether it’s a particular AA group or something other than AA. But being in contact with people who are also addicts, and getting that support from someone who has been there, is so important for so many in recovery. Not everyone, no, but many.
You are rebuilding your life. Your body is rebuilding, your brain is rebuilding, you are discovering what life is like without the friend/veil/entertainment of alcohol. You’ve been stripped down and are building back up. That takes time. There will be some paths you follow that will be abandoned, there will be false starts. Just remember it’s a process. You’ll never be finished, but if you stay mindful of the process, then things will get better. As Lyle Lovett sang, “What would you be if you didn’t even try? You have to try.” So just keep trying. It’s all you can do.