Mick Jagger mourned the death of girlfriend L'Wren Scott's March 17 suicide in a heartbreaking note on Facebook; "I am still trying to understand," he wrote Credit: Kevin Mazur/WireImage.com

Mick Jagger is mourning the loss of a great love in his life. On Tuesday, March 18, one day after his girlfriend, fashion designer L'Wren Scott, was found dead of an apparent suicide, the Rolling Stones rocker took to Facebook with a heartbreaking tribute to his late love.

"I am still struggling to understand how my lover and best friend could end her life in this tragic way," Jagger, 70, wrote alongside a beautiful black-and-white photo of former model Scott, whom he had been dating since 2001. "We spent many wonderful years together and had made a great life for ourselves."

"She had great presence and her talent was much admired, not least by me," he continued. "I have been touched by the tributes that people have paid to her, and also the personal messages of support that I have received. I will never forget her." 

As previously reported, Scott was found hanging in her New York City apartment on the morning of Monday, March 17. Shortly after news broke of the tragedy, Jagger canceled a Rolling Stones concert in Perth, Australia, and made plans to fly back to New York. A source told Us Weekly that the rock 'n' roll legend is "terribly devastated" and "inconsolable."

Other stars have been paying their respects to the late model/fashion designer, too. Vogue Editor-in-Chief Anna Wintour, for example, remembered Scott as "kind" and "so much fun," and Nicole Kidman's rep described the actress to Yahoo! as "heartbroken and in shock."