A lot of the addictive substances in cigarettes work TOGETHER. For example, nic increases dopamine, and MAOI's stop them from being re-absorbed. The result is LOTS of dopamine floating around in your head.
I wonder if, when you remove one or the other, it lessens the grip of the addiction. Because now, it's just the nicotine. There's no MAOI's, like there is in cigs. So maybe nicotine on its own is simply not as addictive as the two combined. Maybe this is also why some people continue to crave cigs no matter how high nic they use. They're craving the MAOI's, not the nic.
For those really bad moments, I have a small supply of snuff (you can also use snus) that I keep around. These products are smokeless tobacco, and do contain MAOI's, but due to the lack of additives, and lack of combustion, they are not associated with severe health risks to the same level that smoking is.
I have found that if I'm really doing bad and I'm about to break down and have a cig, a bit of snuff takes that urge away, and I don't want a cig anymore. I don't use it much at all - I've had it for over a month (maybe two?) and I've used it once. But it's nice to know it's there, for when the craving feels out of control and vaping isn't helping.
MAOI's, in addition to being addictive, are also anti-depressants and anti-anxiety. This may be why you crave them in stressful times. You've essentially been medicating stress with cigs.