Did you buy freebase or salts? And what mg/mL did you dose at? I still use my reusable vape and dose my own and have dosed both freebase and salts - what MalReynolds says is the truth. The salt has a much lower throat-hit, which has allowed the disposable vape companies to jack up the mg/mL to 50+ which is just fucking insane territory. A friend of mine dosed his own with nicotine salts at 50mg/mL to compare and it gave that exact head spin you’re talking about. It’s a combination of the dosage and use of nicotine salt that does it.
We were taught a similar trick in physics - point your right-hand thumb in the direction that current (or electrons, same same) is travelling and the curling of your fingers shows the direction of the resultant magnetic field that the current creates.