Not being a expert ,but i think copper can cause both fatigue and insomnia. I been having both when my unbalance lives or change, sometimes i feel like needing to sleep 10-11 hours, and then other time i have some insomnia where i can sleep poorly maybe 3-4 hours.
Or maybe you have just cleaned enough your body from copper and other heavy metals and you can sleep more normally now.
Insomnia is bad for recovery, as we need lots of rest to get healed.