Sarah Jessica Parker reacts to 'unbearable' loss of her 'Sex and the City' co-star Willie Garson

Garson died at 57 of pancreatic cancer.

Sarah Jessica Parker has broken her silence about the death of "Sex and the City" co-star Willie Garson.

In an Instagram post Friday, Parker wrote that the loss has been "unbearable."

Garson, who played Stanford Blatch on the HBO series and subsequent films, died of pancreatic cancer on Sept. 21. He was 57 years old.

"Sometimes silence is a statement. Of the gravity. The anguish. The magnitude of the loss of a 30 + year friendship," she wrote. "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."

"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," she continued. "Your absence a crater that I will fill with blessing of these memories and all the ones that are still in recesses yet to surface."

Garson's son, Nathen, first confirmed his father's death on Tuesday in a social media post, sparking responses from several "Sex and the City" actors, including Kristin Davis, Cynthia Nixon and Kim Cattrall. The cause of death was later revealed in a New York Times obituary.

"My love and deepest sympathies and condolences to you dear Nathen. You were and are the light of Willie's life and his greatest achievement was being your Papa," Parker added in her post. "These were his last words to me. 'Great bangles all around.' Yes. Godspeed Willie Garson. RIP."