
Baby that’s because nicotine changes your brains processing time and emotional response; it’s a self fulfilling prophecy. Nicotine addictions are a step up from caffeine, but the cycles are similar. Caffeine blocks receptors responsible for regulation of sleep and stimulus response, so your body makes more of them, then when you have lower intake you feel more tired, lethargic, head hurts, etc. etc.
I’m not trying to persuade you that nicotine bad so you should quit (I vaped for yearsss), but the “benefits” of nicotine can be much more easily felt with proper medication, routine, regulation, etc. I was a fiend until I accidentally got diagnosed for adhd, then got put on stimulants.