the circadian rhythm aspect made me think of b12.
i went looking for possible nutrient depletion aspects of lunesta.
http://www.tuesdayminute.net/Drug-Induc ... 20TM-1.pdf
Ambien®*, Lunesta®, Restoil®, Sonata®
However, since many sleep aids/sedatives act on the GABA-A receptor complex, it may be deduced that they “may” act similar to anticovulsants
which also act on the GABA-A receptor, and whose depletions included:
Biotin, Calcium, Folic Acid, Vitamin B12, Vitamin B1, Vitamin D, Vitamin K
i'm pretty sure this site's table has been built from this book
they add a list of their own products in order to address the probable deficiencies.
personally i would look at what supplements you're currently taking, and whether there are some gaps or timing issues that could be addressed.
taking b12 in large amounts at the wrong time of day can affect your night's sleep.
b-complex vitamins and magnesium are great for fighting anxiety. besides food, such as dark green leafy veggies, the best magnesium form i've run across to date (thanks to shye) is magnesium glycinate. a high potency b-complex, such as a b-100, might also help you out.
anyway i hope you get relief, sleepless nights are no fun...