The SNP leader revealed the extent of the personal toll that left her “completely overwhelmed” as she weighs up life and death decisions every day.
“If you feel utterly exhausted by it all, believe me, you’re not alone,” the First Minister told supporters in a virtual speech to SNP conference.
“Politicians usually run a mile from admitting human frailty, but these aren’t normal times.
“I don’t mind saying that these last nine months have been the hardest of my life.
“I’ve had many dark days and sleepless nights, struggling with the horrendous choices the pandemic has forced upon us.
“At times I’ve felt completely overwhelmed - as I’m sure many of you have. And I feel a deep sadness for the lives that have been lost.
“Not a single day passes that I don’t think of families who are grieving.”
Governments around the world have been grappling with “impossible decisions” , she added.
“Every action necessary to reduce the harm of the virus and save lives puts jobs and businesses on the line and causes suffering in so many other ways. But without those necessary measures, more lives will be lost.
“I’ve done my best to get these decisions as right as I can."
The SNP leaders hailed the support of her “outstanding” team of ministers and advisers.
But she added: “I know we’ve made mistakes and the responsibility for that is mine and mine alone.
“I feel it deeply, and I always will.”