Meg,
thanks for coming here and posting. You really need to get yourself some help. Drinking before work, is not normal, and a sign you have problems with alcohol. You sound like you REALLY want to quit in this post, and I think you should. Don't be concerned with the "alcoholic" label. If you feel like it's doing anything bad for you, then you should stop. Tell your coworkers you aren't going out. You have to give up that stuff, or the cycle will never end.
best of luck to you!! ((((hugs))))