Badditude again posted what I was about to say... I am no doctor, but I have done tonnes of research on Nicotine and smoking. How smoking addiction works, and what happens. So, take this info from a non-expert.
Nicotine affects the dopamine receptors in your brain. It was intensified by other chemicals in a cigarette. When you switched to Ecigarettes, it still triggered the dopamine receptors from the nicotine, but got rid of a lot of other garbage that went with the regular cigarettes.
You gradually weened yourself off of the NIcotine.. but.. the dopamine receptors have made permanent connections. This is why there are so many relapses from people who have quit cigarettes, and why stressful situations cause relapses. You have the addiction to inhaling a substance, and the physical aspect of smoking. Vaping fills most of those gaps, since it is used in a similar method to smoking. It is also why it is a more effective means to stop the cigarettes.
IF you can stop the physical aspect, by all means, go for it. Try weening yourself, or try to break the habits you already have.. if you normally vape while driving or on the computer, then change those habits. Vape in the kitchen, or somewhere else you normally don't vape. One day, you may kick the habit entirely, but I would keep an ecig handy.. I would rather you be vaping then turning full circle and smoking again.