I made the mistake of being over-confident in my sobriety.
On the contrary, I think you lost all confidence in yourself and sobriety. A confident sobriety and alcohol consumption are just plain mutually exclusive. This is the point that our AV tries to obscure with all sorts of yammer and blather.
I think we need that confidence in sobriety and ourselves as a necessary component. In fact, it forms the basis of our commitment to sobriety and to ourselves.
For me, it was acceptance that I am no longer an alcohol consumer, I don't drink. At all. In any amount. Ever. Then confidence in my sobriety was set to 11. Any thoughts to the contrary, either of drinking or of lack of confidence, were assigned to my need to feed my AV and therefore 'not me'.
Is there a plan about continuing to use alcohol? Ever? In any amount? Under any circumstance? This is a starting point.