Sarah Jessica Parker just paid tribute to her "Sex and the City" costar ... saying the sudden loss of Willie Garson is a crater in her life -- one she's trying to fill with memories of their time together.
SJP poured her heart out Friday ... saying she'll fondly remember their 30-plus year friendship that included road trips, meals, late night phone calls, a devotion to parenthood -- along with all the time they spent on sets ... "most especially Carrie's apartment."
She added, "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."
Sarah also expressed her condolences to Nathen ... Willie's 20-year-old son whom he adopted when Nathen was only 7 years old. Sarah said, "You were and are the light of Willie's life and his greatest achievement was being your Papa."
As we reported ... Willie's sudden death sent shockwaves throughout Hollywood. "Bosch" star Titus Welliver broke the news saying, "There are no words. I love you dear brother. We are fewer." Our sources say Willie had been battling with cancer.
He had a huge HBO following as Carrie's BFF in 'SATC' but he also appeared in a ton of other TV shows. He was only 57.