I have a friend that can easily go through 2 packs of cigarettes in one night while drinking. He smokes outside, so that's 5 minutes inside, 5 minutes outside, repeating until he passes out. He's not sitting them in an ashtray and forgetting about them, and inhales completely. My grandparents smoked 3 packs of Lucky Strikes a day for decades, until it killed them. More than one pack a day used to make me sick. There are different tolerance levels for different people, but there is a universal limit. It is a poison in large quantities after all.
If you really like the flavor you are vaping and just can't put it down, a lower nicotine concentration is probably a good idea. There are other ways to get TH than just the nicotine. Whether or not you cut down the nicotine level, the more you vape the more water you need to drink, don't forget to hydrate. If you don't have any problems with PG yet, too much vaping might push your tolerance of PG to the limit. I vape about 3ml a day of 16-18mg right now. I learned what too much at one time was the first time I found a flavor I really liked. YMMV, etc.