Remember that every day is going to come and go in 24 hours, whether you are drinking or not. I used to get big anxiety about not having any booze to drink, so the thought of being sober that evening was literally scary. But it turns out the day kept chuggin' right along even when I quit drinking, it was really a lot less awful than I thought it would turn out to be.
Once I got over that mental hurdle I had to figure out what to do with the twenty-plus hours a week I used to spend drunk off my ass, that was the next obstacle for me.