There are no words to truly describe this right now, but Ashley Cain and Safiyya Vorajee are facing every parent's worst nightmare.

On Sunday, The Challenge star and his girlfriend confirmed that their 8-month-old baby girl, Azaylia Diamond, had passed away.

The little girl succumbed after a battle with leukemia.

Cain has revealed the horrible news of his daughter being diagnosed with this illness back in October, not long after she was born.

He wrote on Instagram following her passing:

"Rest In Paradise Princess 👼🏼🌈I will always hold you in my heart until I can hold you again in heaven ❤️😢 #AzayliaDiamondCain."

Added Vorajee in a heartbreaking tribute of her own on social media, following the loss of her child:

"You are my Angel my heartbeat my soul."

"You will always be with me like a handprint on my heart."

"RIP my precious baby."

This past autumn, the 30-year old reality star revealed that Azaylia had been diagnosed with a "very rare and aggressive form" of leukemia, a blood cancer.

Over the next few months, the infant went through treatments in the hospital, as Cain kept followers apprised of her condition.

Tragically, they were not able to save her. 

On April 8, Cain said her cancer spread to her brain, stomach, spleen, lungs and kidneys.

At that point, doctors told the family they thought "she's only got one, two days to live."

They told the parents to "make the most" out of this time with her, however long it might be.

How did he respond to that?

"I'll tell you one thing, I ain't got no plans for going anywhere this weekend," he wrote.

"I'm an optimist. I'm a believer," he told fans, after hearing from physicians.

"I have a positive mind frame and I know her strength and I know mine."

In a heartfelt Instagram caption on April 23, Vorajee said that when she sees her baby girl's face first thing in the morning, her "heart instantly overflows with abundance of love for you."

She added that Azaylia's eyes have been "intensely dry," requiring eye drops "so her eyes can move," and that her care is around the clock "24/7."

Just so unbelievably tragic.

During the two weeks the couple had their bundle of joy at home in April, they took Azaylia on walks in the area for the first time... let her play in a jumper ... and fed her in her high chair.

Just a day before the brave young girl passed away, she suffered a seizure that marked the beginning of the end of a beautiful young life cut tragically short.

Wrote her grieving dad shortly afterward:

Your determination inspires me.

You impress me each and every day.

I'm so proud of you. I can't imagine my life without you.

I have faith in you. My Champion. My Hero. I love you.

Two days before announcing the child's death, Safiyyah shared sweet photos of Azaylia sleeping in her stroller.

These words are hard to read, for us as outside observiers, let alone for her to write, as a grieving parent.

"Giving her 100% everyday is what she was promised, even when her eyes are closed I talk sing and shake her fav rattles so she is constantly surrounded by a positive vibe," she wrote.

"Appreciating the day the hour and the min is something I never thought I would do as we all take life for granted."

We send our heartfelt condolences to Ashley Cain, Saffiyya Vorajee, and their families during this unimaginable time.

May beautiful Azaylia rest in paradise.