On the brink: You wrote in part, "Why do I do this to myself?? I feel so broken."
Good question. To shed light on an answer it might be possible to focus on the reference to "I", "myself". You say that "I am doing this to myself". Could it be that with addiction the "self", the "I" is divided against itself? In a way there are two "selfs", one the old preaddictive self, numbed by alcohol, and now under the influence of a more primitive "addictive self" residing deep in what has been called the "lizard" part of the brain, the seat of emotions, fears, cravings. Since the body's physiology and chemistry have changed this primitive part of the brain does everything it can to keep up the supply of alcohol. Hence you are indeed doing it to yourself. The way out is to diminish and finally end the power of the addictive self, something which is possible through a recovery program, such as AA or Rational Recovery. I also found helpful the companionship and advice of other alcoholics in recovery. It's a repair job and it's not easy. Changing back the chemistry, the physiology and subduing the influence of the addictive part of the brain. Others have done it. You can.
W.