Hi cdngreeneyes,
Welcome to the forums and congratulations on one week of being smoke-free!
Sorry that you are having a rough time of it right now. Yes, that first week and even the first few weeks can be quite nerve-wracking. Sometimes, it feels like that little voice demanding a cigarette will never shut up. But it will, my friend. It just needs to know that you are serious about saying "no" to another smoke.
So, there are a few thoughts I want to share with you.
First, it is OK to express frustration, angst, fear, or any other "negative" emotion you might be having right now. Yes, we all strive to maintain a positive attitude, and that is certainly part of the winning formula. However, quitting nicotine can take a lot out of a person emotionally, especially at the beginning. So, while you need to keep re-directing yourself to positive thoughts and images, realize that it is OK to honestly acknowledge your feelings, too. ...Hopefully, that makes sense.
Second, if you have been off all nicotine for 7 days, your physical cravings are over. (Those end by the end of the 3rd day.) What you are feeling is the psychological longing and powerfully close memory of nicotine addiction. Yes, a psychological craving can very closely mirror a physical one, but the physical part really is over for you right now.
Third, this is the reason you don't want to have "just one" cigarette right now. Since you are already physically detoxed, you have gone through the hardest part. If you partake in nicotine at this point, you will re-ignite real physical cravings again, and that will go on until the nicotine leaves your system again. Just one cigarette would probably be out of your system in less than 3 days, but why would you want to go though those physical craves again for even 3 hours..or even 3 minutes? Believe me, this is one of the big deterrents to me trying one again; I do not want to re-live physical detox.
I know the battle right now is exhausting, but please keep it up. Each time you say "no" to a craving, it gets a little bit weaker and you get a little bit stronger. It will get a little bit easier tomorrow and the next day. ...And if you are utterly exhausted from fighting, just go to sleep. It can help a lot.
Keep reading and posting as much as you need right now. There are people here who like to help. Hang in there.
You are really doing great so far, so just keep on taking it one day, one hour or even one minute at a time if you have to! I see you have gone through much of the Program and have learned a lot about quitting and addiction. A lot of this quitting process is learning how to stay quit and cope with those exhausting withdrawals. 
I think that the best thing that you could have done was to log in and write about it! It has a way of helping you think about it and usually that will help you to realize that it just isn't worth it to smoke again! 
