The previous works because you're putting yourself in a state of anxiety and creating adrenaline as a result. Your brain can run on adrenaline instead of dopamine, so it does that. If you learn to cope this way you'll be fucked in old age like me though. In addition to adrenaline, you're filling your body with cortisol and that will destroy you from within. Don't do it. Just go get the damn ADHD medication.