hi beeme -- I can relate, I stopped before I "had to". On most occasions I could still control my drinking, although it was increasing over time. I was building up tolerance, so I could drink 4 glasses of wine and not feel drunk, and I did that lots of nights. On just a few occasions I lost control -- drank too much at a company party, and didn't remember the last half of the evening. Drank too much at a baby shower and drove home drunk.
Those were warning signs to me, and I also had negative moods and anxiousness as you described. I was starting to obsess about alcohol -- just focused on planning my evenings around a bottle of wine, and didn't want to do things that didn't involve wine.
So that's it ... no DUI's, no warnings or ultimatums from anyone around me such as my employer or family. I was just beginning to sense that the elevator was headed down, and I wanted to get off before it went further. I've been sober one year, and I don't regret it.