Nicotine hits me harder in vaping. I monitor myself and have a pretty good rhythm down to know when to vape. Nicotine is a stimulant, but without all the other chemicals present from the combustion of tobacco, you aren't really going to get any calming effect (at least I don't). I have since started vaping WTA (from Aroma) and it actually counteracts the effects of too much standard niquid vaping, and, it generates very closely to the overall sensation (without the chest pain) of a cigarette. I am really pleased with my juice line-up now. Too much vaping is relative and only your body can discern what "too much" is. I don't mean to be funny, but ask your body if you have had enough. Also, I don't exactly know if vaping is a pit-stop to quitting nicotine altogether, or more of a migration to another form. I remember thinking I was only going to be vaping for half a year, but that was a year and a half ago...
p.s. I think you will be fine!