How can I withdraw from a 3 year habit of taking a 2mg lunesta (eszopiclone) for insomnia I've had since childhood? Past 3 nights, no pill, zero sleep, headaches.

Try this. Simple things to try are no caffein in the day, exercise, stop computer/tv screen exposure in early evening, sleep in total darkness, get in bed by 10 pm, take melatonin 3-12 mg about 30 minutes before bed. Melatonin is good for you & your brain, is available in vitamin stores, will not interfere with sleep cycles. Other supplements good at bedtime are magnesium 400-800 mg, l-theanine 100-200 mg.
Insomnia. See u pcp for evaluation , these medication r intended to be taken on as needed basis only . Since u seems to be addicted to it , u pcp can give some medication to help u sleep.