Does the difficulty experienced the first three days pertain strictly to lack of nicotine or does the frustration of not doing what you are used to also enter in?
I believe it can be one (NRT) or both (CT) depending upon how much nicotine you were using daily immediately before you quit.
On another note: Some people don't appear to take in the information provided and use it to their advantage. It seems to go around and not sink in. That keeps them going in circles.
Others take it all in and are wholly involved with quitting.
In either case, you will find you must often bend the thought of smoking over to kick it out of your head and succeed. I have just the machine as shown below. I call it the "bend over nic while I kick you to the curb!" machine.
Enjoy your weekend & Don't smoke it up!