Why do I wake up some days feeling full of positive energy, then by mid-day I'm really down & depressed

That sounds very challenging, and I will try to answer my best with the information that I have. Alcohol is considered a depressant and because of that it has all different effects on the body. Because it is a depressant, it can often do things like calm anxiety, help people feel asleep, reduce their inhibitions, and reduce levels of stress. I suspect that you likely had anxiety, depression, and issues with sleep prior to stopping alcohol but they seem more amplified now that you have stopped drinking.

It is important to note that there are a lot of different things that can help with those symptoms. Having a counseling to talk through your depression and anxiety will help with your mood, as they can help you work through some of the root causes of depression and anxiety, and give you alternative tools and skills to cope. In addition to therapy, talking to your primary care doctor about your symptoms could be a way to discuss your concerns more thoroughly and get feedback.

As far as the difficulties with sleep, there are also various things that can cause issues with poor sleep or restless sleep. First off, if this has been going on for awhile, it might be a good idea to talk to your doctor about medications, lab tests, or sleep studies to see if there is a medical cause for your sleep difficulties. Other things that can cause issues with sleep are anxiety and depression (and alternatively, a lack of sleep can make people have more symptoms of anxiety and depression). Good sleep hygiene is also equally important, such as avoiding screen time before bed, making sure that your room is a comfortable temperature, trying not to exercise or drink caffeine late in the day, and trying to use your bed for sleep and adult activities only, versus work or others things.

I give you credit for cutting out alcohol, that is a big step, and while it may seem like it is difficult now, with the right support you can gain even more healthy habits and stability.