Everything that is posted about Days 1 - 3 is true and then some, hence the phrase "embrace the suck".
Day 1 and 2 were work days for me, so I was fortunate enough to be able to close my door and work while mentally I wanted to scream because the anxiety was so bad. Day 3 was a Sunday, and it was a 16 physical withdrawal day, headaches, stomach cramps and zero energy, basically the flu without being sick. And I will never have to go through that shit again as long as I quit today, wake up tomorrow and quit again.
Get through day 3 or 4 , and your eye will be open to a life of quit. I hope you can make the right choice.