"The Wire" standout died on September 6 and on Wednesday, the day of his funeral in Harrisburg, Pennsylvania, Jurnee paid tribute to the beloved actor with a lengthy, heartfelt post on Instagram.
Alongside a black-and-white image of Williams and several snaps of him with her and "Lovecraft" co-star Jonathan Majors on the set, she wrote, "My brother, my heart hurts so. A part of my brain refuses to accept it... s**tty part about grief - it goes in stages. For me, it started w/ [with] denial."
She shared her heartbreaking reaction to hearing the terrible news. "When (my brother) @jakesmollett called to tell me, my brain went 'hell naw that's not true, let me call Michael.' And I called him. I called him over & over until my brain said stop, he's gone."
Michael received his fifth primetime Emmy nomination for his work on the series and was due to be in Los Angeles this week to attend the big award show on Sunday, September 19 with his "Lovecraft Country" castmates.
"We were gonna dance, celebrate, cry. Instead our brother was laid to rest today. I still can't make sense of it. Perhaps it's selfish of me to want to hold onto this beautiful man that came into my life & forever changed it..."
"I take comfort in knowing that you're finally free, somewhere dancing, being mighty, showing the angels how to really get it," she concluded her message. "Btw [by the way] - You still owe me that dance...& our [NBA team] Bulls Jerseys. I love you."