Hi and welcome to ECF. If you aren't having issues at 18 mg/ml in your setup, I'd kind of just recommend "carry on." If you start feeling lightheaded, nauseous, dizzy, hiccups, yawning, fatigue will those can be signs of nicotine overload. Chain vaping is
totally normal in the beginning, so you may find you vape less after you fully detox. Your "brain" is telling you it "needs" a cigarette, and vaping provides SOME satisfaction by providing nicotine, but you may still feel a bit wonky as detox progresses, it's kind of the nature of the beast.
I vape at 18 mg/ml nicotine and I was a 3 ppd smoker. Your mileage may vary, as everyone responds to nicotine from vaping differently.
If things get really awful or aren't working, post. I'd suggest some strategies if you are having trouble, including perhaps a higher nicotine tank for those "bad" moments and if things get really dire and you feel yourself at risk for smoking, there can be additional (but more expensive) remedies, so unless you feel at risk of smoking, I won't list them.
I will say, finding the right vape equipment (for you) and the right juice is important, but it sounds to me as if you may already be there (with a setup and juice you enjoy). I will say you may want to get another setup as a backup (it doesn't necessarily have to be a super expensive one either) in case your primary mod fails.
If you are interested in that, I might post about what you like/dislike about your current setup and etc.
Best of luck and welcome
Anna