Well thanks guys

also I meant like me doing an INSTANT drop from 12mg to 6mg would affect me
Doubt it.
The basic thing going on with this nicotine stuff is us nicotine addicts (well, we are) get used to having some amount circulating in our blood streams all the time. Whatever amount is normal for whichever person you're talking about. When it drops below some level, we crave the stuff. When you smoke, you reach for your cigs. And probably didn't think about it much. You just go by feel that the level is low and you need a "fix" right?
(Or if you have to go a long time in a "smoke free" situation like flying, you get "nicotine fits" and all)
You just try (without thinking about it really) to maintain a level of nic in your system. Ever try switching to "ultra lights" or knew somebody who did? That's lowering the nic level suddenly. You just end up smoking more cigs to hit the same nic "target" (I did the ultra light thing, one of the "I wanna quit brands", the "cutting back" thing don't work

).
If you're getting negative effects from the nicotine, you're already vaping enough to deliver
too much nic at your current level. "Too little" (which can cause "nicotine fits" and such) isn't the problem in this case. You're overshooting your level (whatever that level is for you).
But "withdrawal"? Nah. I often use 18mg in the morning for a while then switch to 6mg to coast a long much of the day. I don't do anything "gradual". I take one clearo off the battery and put another one on. Never miss a beat.
Seriously, though, if you're getting bad reactions from too much nicotine, it'd be better to drop way down on the nic level then, if necessary, move up
gradually to find the level that works best for you. Worst case scenario in a "too low" situation is you chain vape. Big whoopee. That's pretty trivial compared to making yourself sick.