It's been almost four years since I quit. Day three was the toughest for me and then it the physical craving started to get better. Once the withdrawals are over, your home free as long as your mental attitude is committed to never, ever have even one drag ever again as long as you live.
Every day I'm thankful that I am a free man at last and will never be a slave to nicotine again.
Hang in there, your future self will be eternally grateful.