Strategery, I still am pretty self-critical, but no longer take it so personally, if you know what I mean
Really probing my past and discussing it with others has brought me to realize I'm no worse than many others have been, and asking for help or others' input with many current decisions has helped me do better as I go forward. This at least allows me to take responsibility for my deeds in a conscious way.
A lot of my sense of worthlessness came from knowing that I was in fact guilty of laziness, deceit, and manipulation of others to cover my alcoholism, to name just a few things. I felt like a fraud and I was one. Owning up to that and trying not to perpetuate those faults has taken a long time, and it will be longer before I completely lose that habit of doubting myself. But close examination of myself has helped stay sober, because I acknowledge that I can and must make changes in many dimensions, and if I drink again, it will be much more than a physical relapse.