Thanks for all the encouragement and advice.
I'm feeling a bit better now. I really really needed to get to the gym to release some tension, but it closed early yesterday and I couldn't make it til this evening. Now my head is much clearer.
In my last few attempts to quit, I don't think I made a very honest commitment to myself to do it. I kept old habits, and you can guess what happened. Despite making it 7-10 days before, I hadn't really changed anything. This time, I'm recognizing what knocks me off the wagon and altering course... thus the anxiety, since I'm taking away my crutch. My really big crutch.