Yeah, i dont know who comes up with those lists, you need to be at least at 24 mg unless u extremely motivated (i.e. being forced to quit) go to 24 mg, if thats too harsh, take a few hits, wait a few minutes then take a cpl light hits, then gradually deeper hits (it should go away after a few minutes). if u just cant take it go down to 18. If not stay there or go up to 36mg and do the same thing. If it wasnt too harsh to begin with, go up to 36 mg also and do the same thing, take a few hits, it'll almost definitely be harsh, wait a few minutes then take a few light hits then a few deeper hits and than you should be fine, if not drop back down to 24 mg...try to power thru for a cpl weeks even if u still want to smoke, it will take that long for your brain to get used to not engaging in the actions related to smoking.
If you feel like its all too harsh and never gets better after a few hits, then switch to nic salts, u can use them in a subohm tank, u just have to pay a little more attention to what u r doing, they have a lower boiling point. They do have a different absorption 'profile' for lack of a better term, but it mimicks cigarettes very close, so you would be vaping the same regularity as u would be smoking.