should I take 2mg or 4mg?

vape/smoke after 30 minutes of waking up?

Try the 2mg. Expect to use ~10 pieces a day for the first weeks.

vape/smoke within 30 minutes of waking up?

Try the 4mg. Expect to use ~20 pieces a day for the first weeks.

why take nicotine to quit nicotine?

Your brain creates more receptors to catch nicotine when you vape or smoke. A bunch of empty receptors cause intense cravings and withdrawal. Tapering off nicotine as your receptor count gets back to baseline is easier (and more successful) than going cold-turkey.