The 48-year-old writer penned a heartfelt tribute to her "love" and "muse" in an Instagram post Thursday after Rayya Elias died of cancer at age 57.
"She was my love, my heart, my best friend, my teacher, my rebel, my angel, my protector, my challenger, my partner, my muse, my wizard, my surprise, my gift, my comet, my liberator, my rock star, my completely impossible non-cooperator, my otherworldly visitor, my spiritual portal and my baby," Gilbert wrote.
"I loved you so much, Rayya," she said.
"Thank you for letting me walk with you right to the edge of the river. It has been the greatest honor of my life. I would tell you to rest in peace, but I know that you always found peace boring. May you rest in excitement. I will always love you."
Elias, a songwriter and short filmmaker, was diagnosed with pancreatic and liver cancer in spring 2016, according to People.
She rang in New Year's Eve with Gilbert shortly before her death.
"Happy New Year, everyone," the author captioned a photo with Elias on Sunday. "You made it. We made it. Blessed be. #2018."
Gilbert confirmed her relationship with Elias in September 2016 following her split from husband Jose Nunes.
She and the songwriter celebrated their love with family and friends at a commitment ceremony in June.
"Today was precious and perfect. A simple and spontaneous ceremony of love, surrounded by a small handful of friends and family," the star wrote at the time.
"Our ceremony was nothing legally binding ... just a quiet and private celebration of what we have long known to be true: We belong to each other."
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