Every craving passes eventually no matter how uncomfortable. At first you think about it all the time.... then little by little, you'll think about it less, until you don't think about it at all. Listen to yourself and how often you think about it. Breathe. Just breathe.

if you smoke now, then last 60 hours have been a waste

Yes, do something physical that you enjoy, and sweat!! Take the toxins out!

I've never smoked tobacco habitually, but maybe the gum could help you taper off and quit? And maybe asking AI for quitting advice could help.