Vaping gets you your nicotine; smoking gets you nicotine and a few other addictive substances (there are good threads about it here - you can probably find them by searching for "alkaloids").
So, although you've got a source of nicotine, you're still going through withdrawals from the other chemicals in tobacco.
Many people will, when in withdrawals, replace the missing substance(s) with something else. Food (sometimes just sugar) is very common.
I've watched a close friend go through this over and over. I always know when he's "quitting" drinking (it isn't really quitting if you "quit" monthly) because he leaves a trail of candy wrappers everywhere he goes.