I think that what you are experiencing is common Kevlar. There certainly are some people who can just one decide they are going to quit drinking and then just "not drink" forever. But I think most of us have to do some active work to make sobriety part of our lifestlye..vs just white-knuckling it as you seem to be doing. Maybe going back to AA as you have done in the past will be that answer - because the 12 steps and the process involved with them is a very life-changing process, and an ongoing one. Many other sobriety methods are the same - they are ongoing and they achieve positive change in many areas of our lives along the way.
My personal tools are SR, counseling, mindfulness and meditation and I do a little of some of them each and every day. Not counseling as i could never afford that, but I review what I learn in my past sessions and help apply them to my life. A practical example would be that through living a mindful life, the question of whether I will "never drink again" really doesn't even come up - because I know that my focus needs to be on today and now. Sure I can think about the future, but it reminds me that I cannot possibly control something today that happens 10 years from now.