I've had this too. Have you talked to your doctor? I tend to "self-medicate" with alcohol and removing the alcohol doesn't remove the underlying problem. In my case, my doctor diagnosed seasonal affective disorder and I started using a light box, which helped tremendously. Not trying to give medical advice, just saying sometimes the alcohol--or lack thereof--is not the real problem, but it's really easy for us to just assume it is.
Take care,
MM