Alyssa Scott, mom of Nick Cannon's late son Zen, posts emotional tribute after loss: 'It feels unbearable'

Alyssa Scott, whose 5-month-old son with Nick Cannon died on Sunday, is paying tribute to her "sweet Zen."

The model shared her heartache in an Instagram post, admitting that while it feels "unbearable" in the wake of the baby's death, from brain cancer, it will forever remain an "honor and privilege being your mommy."

"Oh my sweet Zen," she began. "The soreness I felt in my arm from holding you is slowly fading away. It’s a painful reminder that you are no longer here. I caught myself looking in the backseat as I was driving only to see the mirror no longer reflecting your perfect face back at me. When I close a door too loudly I hold my breath and wince knowing a soft cry will shortly follow. It doesn’t come. The silence is deafening."

Scott spoke about the child's cancer journey, being diagnosed at two months, having surgery and then it becoming clear at Thanksgiving that the end was near.

"These last 5 months we have been in this race together," she wrote. "We would hand the baton off to each other. You kept me going. It would be the middle of the night and you would smile at me. A surge of energy would fill my body and pure joy would radiate from within me. We were a team, both determined to see it through. It feels unbearable running without you now. I can't."

However, amid her grief, "I feel myself being carried," she wrote. "By your sister.. By God. By complete strangers encouraging me to not give up."

Scott ended by writing, "It has been an honor and privilege being your mommy. I will love you for eternity."

The video, set to the song "Promises" by Jhené Aiko, showed sweet scenes from Zen's short life — as a newborn having his older sister read to him and playing with a keyboard. But also being wheeled into surgery and recovering post-op — as Nick explained he had a shunt put in to drain excess fluid as the tumor in the baby's head grew.

Nick announced Zen Scott Cannon's death on his talk show Tuesday, calling Scott "the strongest woman" and "best mom."

Nick has faced criticism for continuing to shoot his talk show in New York — as Scott grieves in California — which he spoke to on his show Wednesday.

"A lot of people keep asking me, 'Why you even at work?' Especially my family," Cannon said. "'Boy, you need to go sit down somewhere. You got too many jobs already anyway!' I appreciate all that advice and I know it comes from a place of care, but to me, this isn't work. This is love."

He added, "If I wasn't here, I'd be probably in bed, curled up. But you guys give me a reason to get up and get out of bed."

Nick also praised Scott again for how she's handling everything.

"People are wondering how she is doing," he said "She is making it five minutes at a time, you know what I mean? You never know how strong you are until being strong is the only option. We here. We smiling through the pain."

Nick's relationship status with Scott remains unclear. He has six other children: 5-month-old twins Zion Mixolydian Cannon and Zillion Heir Cannon with Abby De La Rosa; Golden "Sagon" Cannon, 4, and Powerful Queen Cannon, 1, with Brittany Bell; and, of course, 10-year-old twins Moroccan Cannon and Monroe Cannon with ex-wife Mariah Carey.