Olivia Newton-John had tragically passed away after a years-long battle with breast cancer.MORE: Remembering the stars of Grease who have sadly diedThe news was announced by her husband, John Easterling, on her Instagram, and he immediately received an outpour of love and support as he mourned his wife.Two days after her passing, the 70-year-old has shared another heartfelt tribute to his wife, opening up about their fourteen years together, as well as sending a message of appreciation to all who have extended their condolences.WATCH: Olivia opens up about her breast cancer battleMORE: Dame Olivia Newton-John: Hollywood's tribute to the late Grease starAddressing Olivia first, he said: "Our love for each other transcends our understanding. Every day we expressed our gratitude for this love that could be so deep, so real, so natural."He revealed: "We never had to 'work' on it.