Quitting Nicotine

I began smoking at 16, when everyone in my family smoked, and am now 72. I have attempted to quit using patches, lozengees and gum. Understanding that I probably have undiagnosed COPD, and have shortness of breath that goes with it, I decided to try vaping after seeing two men vaping and talking to them about it. For a very short time, I smoked and vaped at the same time but soon was just vaping using ELiquid 12, menthol with no withdrawal symptoms. My question was how to reduce the amount of nicotine in the liquid until I was getting none. There seems to be no guidance here as to when and how this should be done. I am now vaping with menthol eLiquid with no nicotine and feel no withdrawal symptoms. However, understanding that menthol addiction can be a problem too, I wonder if I should stay on this course or change somehow. Is there any research information about vaping with no nicotine with a flavor, be it menthol or anything else? Has anyone else totally quit nicotine in this way? My goal is to vape without any nicotine at all. Do many who vape for years, vape without nicotine or do they still vape with nicotine. In my mind if you still vape with nicotine you have not broken the habit. Would love to hear others who have taken this step.