In a candid essay published in The New Yorker on Thursday, March 21, the actress detailed her health battle, which began when she was 24 and had just begun filming the hit series. The second occurred following the fantasy drama's third year.
"My job - my entire dream of what my life would be - centred on language, around communication (and) without that, I was lost," Clarke writes.
The initial aneurysm led to temporary aphasia, which impaired her ability to speak, leading the star to grow despondent and wish for death.
"Even as I was muttering nonsense, my mum did me the great kindness of ignoring it and trying to convince me that I was perfectly lucid," she shares. "But I knew I was faltering. In my worst moments, I wanted to pull the plug. I asked the medical staff to let me die."
The actress' darkest moment came during her second surgery, which left her "screaming in pain."
"The procedure had failed. I had a massive bleed and the doctors made it plain that my chances of surviving were precarious if they didn't operate again," she notes, "I do remember being convinced that I wasn't going to live."
Thankfully, the actress has made a full recovery and credits the support of friends and family for helping her through the difficult time.
"In the years since my second surgery I have healed beyond my most unreasonable hopes," she reveals. "I feel endless gratitude - to my mum and brother, to my doctors and nurses, to my friends."
The 32-year-old also leaned on her father, who passed away from cancer in 2016.
She writes, "Every day, I miss my father... and I can never thank him enough for holding my hand to the very end."