Tragedy struck Demi Lovato and her family over the Memorial Day weekend, as the singer revealed on Saturday that her great-grandmother ("Mimaw," as she affectionately called her) passed away that morning. The "Confident" singer poured her emotions in a series of Instagram posts celebrating her life.

"This morning I lost my world and the world's most special woman," Lovato begins in her tribute. "I miss her more than words can even describe. There is an emptiness in my heart that only her spirit can fill and I pray that I will feel her by my side every single day until we meet again."

Lovato went on to credit gaining her strength and spirit from her Mimaw. "She held on when she lost the love of her life.. The one she was married to for 53 years. She smiled even though she lost a son just this year. She told everyone she loved them every single chance she got and she joked even when her strokes left her unable to speak properly."

"She was my great-grandmother but we were so close that I never knew it was possible that anyone could have the bond that we shared even 70 years a part," she continues. "The pain I feel is almost unbearable but because of her strength I will power through it."

Lovato concludes with a heartfelt message for her great-grandmother: "Mimaw, I hope you are with Papa now.. I hate that I can't hear your voice but I love that you are no longer in pain. I love you so much and I miss you more than anyone could ever imagine. I'll miss your smile, your wittiness, painting your nails and your kisses. I really do love you more. Rest in peace and most importantly rest in the Lord."

Stars We Lost in 2016