Jurnee Smollettpaid tribute to her lateLovecraft Countrycostar,Michael K. Williams, on what would have been his 55th birthday.

On Instagram Monday, Smollett, 35,shared a carousel of photosfrom her time with Williams on the HBO show’s set. The pair’s former castmateJamie Chungalso re-shared Smollett’s post on her Instagram Story.

“Happy birthday, my brother,” Smollett captioned the post. “I miss you so.”

Williamsdiedon Sept. 6 at age 54 after he was found dead in his Brooklyn penthouse apartment.

JURNEE SMOLLETT/ INSTAGRAM

JURNEE SMOLLETT AND MICHAEL K WILLIAMS

“It is with deep sorrow that the family announces the passing of Emmy nominated actor Michael Kenneth Williams,” Williams' rep told PEOPLE at the time. “They ask for your privacy while grieving this unsurmountable loss.”

After Williams' passing, Smollet said she was “struggling” to accept the news that her friend was gone.

I called him. I called him over & over until my brain said stop, he’s gone. I couldn’t breathe. Taken awhile for my brain to metabolize how the world can continue to spin w/out him here in the physical form," she wroteon Instagram. “I take comfort in knowing that you’re finally free, somewhere dancing, being mighty, showing the angels how to really get it. Btw — You still owe me that dance … & our Bulls Jerseys. I love you.”

Michael K. Williams.Amy Sussman/FilmMagic

Michael K. Williams

Williams' storied career included roles inWhen They See Us,F Is for FamilyandMotherless Brooklyn. His role onLovecraft Countryearned him his fifth Emmy nominationin July.

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Williams — who had been vocal abouthis addiction and mental health struggles— once said he’s “very fortunate” for the success he’s had in his career.

“There’s no words to say how fortunate I am, you know?” he previously toldThe Hollywood Reporter. “To keep it real: To be a Black man in Hollywood — not only just to land those two roles, but as a Black man in Hollywood, to go on those two shows back to back, you know, on such a great network as HBO — man, to say I’m fortunate is an understatement.”

If you or someone you know is struggling with addiction, please contact the SAMHSA substance abuse helpline at 1-800-662-HELP.

source: people.com