Sounds tough.
It seems like you carry a lot of guilt over drinking. I think if I was in your state of mind, I would first do whatever I could to cut loose from past failings and acknowledge that they can't hold you back from succeeding THIS time. Rationally compose yourself with the mantra there's no reason you can't succeed this time taking it one day at a time.
That's how I would start anyway. Give yourself a clean slate, mentally. Good luck.