"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 went on to say she will "miss everything about" Garson, and said she hasn't stopped thinking about him since she heard about his death.
She added: "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.
"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. (sic)"
And the actress also paid tribute to Garson's son Nathen.
She said: "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.
"These were his last words to me. 'Great bangles all around.' Yes. Godspeed Willie Garson. RIP."
Garson died on Tuesday aged 57, and Parker had originally spoken about his death in the comments of a post made by Chris Noth – who played Mr Big in the popular sitcom – who simply posted: "Willie", with a love heart and heartbroken emoji.
Commenting on her on-screen husband's post, Sarah wrote: "Thank you dearest Chris. I'm not ready yet. Xxx."
