By Esme Douglas
September 14, 2018 at 06:50 PM EDT

Ariana Grande posted a video on Instagram Friday captioned with a heartfelt message to her late ex-boyfriend Mac Miller.

Grande had previously shared a black-and-white photograph of Miller sans caption on Sept. 8, a day after he was found dead, after disabling Instagram comments following his death.

With her latest post, a quick video of Miller catching Grande filming him and asking her to stop, Grande added an emotional message to the late rapper.

One Love Manchester Benefit Concert
Credit: Kevin Mazur/One Love Manchester/Getty Images

“i adored you from the day i met you when i was nineteen and i always will. i can’t believe you aren’t here anymore. i really can’t wrap my head around it,” Grande wrote.

The singer goes on, “we talked about this. so many times. i’m so mad, i’m so sad i don’t know what to do. you were my dearest friend. for so long. above anything else. i’m so sorry i couldn’t fix or take your pain away. i really wanted to. the kindest, sweetest soul with demons he never deserved.”

RELATED VIDEO: Mac Miller dead at 26 of apparent overdose

Grande has previously discussed the “toxic” aspects of her and Mac Miller’s relationship on social media, specifically Miller’s struggle with sobriety.

“i hope you’re okay now. rest,” Grande ends the post.

Since Miller died last Friday at his home in Studio City, California, many in the music industry have expressed an outpouring of grief over the loss of the 26-year-old rapper/producer.

Miller’s cause of death is yet to be determined, but a source told PEOPLE that Miller, whose real name was Malcolm McCormick, had gone into cardiac arrest after appearing to suffer a drug overdose.