On Sept. 21, actor Willie Garson passed away at the age of 57.

Family and friends are devastated by the news, and the loss hit Sarah Jessica Parker hard. On Instagram, the Sex and the City actress said goodbye to Garson with emotional words.

Sarah Jessica Parker on Willie Garson: "A real friendship"

"It's been unbearable," begins Sarah Jessica Parker, who took several days to comment on Garson's passing. "Sometimes silence is a statement. Of the gravity. The anguish. The magnitude of the loss of a 30+ year friendship.

"A real friendship that allowed for secrets, adventure, a shared professional family, truth, concerts, road trips, meals, late night phone calls, a mutual devotion to parenthood and all the heartaches and joy that accompany, triumphs, disappointments, fear, rage and years spent on sets (most especially Carrie's apartment) and laughing late into the night as both Stanford and Carrie and Willie and SJ."

Parker's tribute to her close friend continued: "Willie. I will miss everything about you. And replay our last moments together. I will re-read every text from your final days and put to pen our last calls."

His absence is "a crater," Parker writes, which she "will fill with blessing of these memories and all the ones that are still in recesses yet to surface."

The actress expresses her deepest condolences to Willie's adopted son Nathen. He was and is the "light in Willie's life," she writes. With the tribute, Parker shared an emotional set of photos from their longtime friendship.

Rest in peace, Willie. The beloved actor died from pancreatic cancer on Sept. 21.