why not supplement with valerian root or preferably l-theanine/lemon balm ?
i was able to cols turkey 15mg zopiclone with valerian root with little to no symptoms, but the 3rd day i felt like i was suddenly very close to a seizure with crazy symptoms acting all at once.
since the zopiclone still helps you sleep,
i would be more inclined to look into the least harmful supplements to help you during the day.
i personally substituted to prazepam to avoid interdose withdrawals but added back some zopiclone afterwards because i got scared cold turkeying the zopiclone was going to damage my brain. prazepam is kind of weak, partial gaba agonist, but in your case maybe herbal thingies could work.