Help, as you know I recently had similar thoughts. I understand the new hurdles your mind has come up with, but I'm guessing most of it isn't true. Sure, you may have been unproductive the last few months, but that happens to many people who have never had a drinking problem. I'm guessing you're just in a rut.
As for being a loser etc. I don't buy it. Whatever you do, don't act on your decision today. Eat something, watch TV or a movie or whatever you do to keep your negative thoughts at bay and get some sleep. Chances are good your outlook will be different tomorrow.