Vidal went public with her heartache on Sunday, May 9 as Americans celebrated Mother's Day, revealing she was struggling to come to terms with the loss of her firstborn, 28-year-old Scott Cohen.
According to Radar Online, the aspiring musician and bodybuilder died from a self-inflicted gunshot wound to the head on April 11.
Former "ER" star Vidal shared a slideshow of photos of Scott from over the years and explained his passing had left a hole in her heart.
"My dear friends... my heart is broken, shattered into 1 million pieces.... I'm in catastrophic grief...," she began. "I'm sharing with you that my beautiful baby boy, my angel, my sweet son is gone... a piece of my heart has been torn away... my beloved Scott Jarred Cohen passed away."
Vidal then shared a few words to her child, explaining how she "very much treasured" life as his mother, calling it "the greatest gift of all, the greatest treasure, the greatest honor, the greatest present that God could give us..."
"You will always and forever be in my heart...," she continued. "It was an honor to be your mom, thank you son for choosing me and blessing me with your life, love, and gift. You're my angel... Rest In Peace my son... I will see you again and we will dance and hug forever [sic]..."
Among the followers sending their condolences were Longoria, who posted, "To the best mama out there, may Scott Rest In Peace. Love you my sweet Lisa," and Vidal's former "Being Mary Jane" co-star Union, who wrote, "I love you & I [love] Scott. We are here for you mama!"
Vidal shared Scott with her husband, real estate agent Jay Cohen. The couple is also parents to Max, 23, and Olivia, 18.