On Monday, X Factor star Tom Mann took to Instagram to reveal that his fiancée and the mother of his 8-month-old son tragically passed away Saturday morning, just hours before their wedding. In 28-year-old Tom’s tribute post to his beloved, he shared with friends and followers how devastated he is over losing the love of his life.

Tom is most famous for his appearance on X Factor and for singing in the band Stereo Kicks. In an Instagram post about his dead fiancée, Tom shared a photo of Dani while she held their son Bowie strapped across her chest in a carrier. The singer confessed that the sudden death left him “completely broken,” but he plans to hold it together for Bowie’s sake.

Tom’s fiancé, Danielle Hampson, was a public relations executive with no known health problems. The cause of her death is still unknown. She and Tom returned from their Sardinia vacation last month. Her death has come as quite a shock for Tom and his family.

Tom said, “I can’t believe I am writing these words, but my darling Dani – my best friend, my everything and more, the love of my life – passed away in the early hours of Saturday morning, June 18. On what was supposed to be the happiest day of our lives ended in irreversible heartbreak.”

He continued writing on Instagram: “I feel like I have cried an ocean. We never made it to the altar; or got to say our vows or dance our first dance, but I know you know that you were my entire world and the best thing that has ever happened to me, Danielle. I will wear this ring that I was always supposed to wear as a sign of my unconditional love for you.”

He added, “I am completely broken trying to process this, and I honestly don’t know where to go from here, but I do know I need to use any strength I can muster for our little boy. I will not be a mark on the parent that you have already become, but I promise I will do my everything to raise Bowie just the way we always wanted. I promise you he will know how amazing his mummy was. I promise to make you so so proud.”

Tom said Dani was “the most beautiful person inside and out” and “the most incredible soul.”

He wanted to let his fans know, “We have lost such a special person, and I am sure we are about to see an abundant outpouring of love that reflects that. I will try to find peace in your messages and comments, but right now, I am grieving, and I will be for a very, very long time.”

He finished his message by writing: “My darling Dani, the brightest light in any room, my world is nothing but darkness without you. I will miss you forever.”