The Shape Of You singer said he would not be where he is “professionally or personally” without the help of Edwards.
Edwards, who lived in Acton, West London, helped launch Sheeran’s career on his YouTube channel SBTV.
He died of a heart attack on Sunday morning after performing a DJ set at a bar on Saturday night.
Sharing an old photo of himself with Edwards to Instagram, Sheeran wrote that he was “speechless”.
“I haven’t posted anything coz I can’t find the words,” he said.
“I can’t reply coz I don’t know what to say.
“Jamal is my brother, his light shone so bright. He only used it to illuminate others and never asked for anything in return.
“A stars light shines for millions of years after they go, and his will continue to light up every dark moment, we are all witnessing his power.
“I would not be here without him, professionally and personally. There will never be anything close to what he is, but I’m so grateful to have existed within his orbit.”
“My brother, come on,” he finished the emotional post.
The post came as the singer made a “low-key” appearance at a vigil for Edwards in Acton before he visited the music mogul’s mother Brenda.
An onlooker told The Sun: “Ed and Cherry went to pay their respects on Tuesday night.
“He kept a low profile and no one bothered him.
“They stayed at the vigil for about 15 minutes before heading to see Brenda.
“He’s told Brenda he will support her in whatever she needs.”
Edwards’ final Instagram post before his death was a tribute to his “ brother” Sheeran.
He wished his friend a happy birthday three days ago, sharing a picture of them together in Marbella.
He wrote: “Happy Birthday to the OG, Ed. Blessed to have you in my life brother.”
In a statement Brenda Edwards, a Loose Women panellist, said: “It is with the deepest heartache that I confirm that my beautiful son Jamal Edwards passed away after a sudden illness.
“Myself, his sister Tanish and the rest of his family and friends are completely devastated. He was the centre of our world.
“Jamal was an inspiration to myself and so many. Our love for him lives on, his legacy lives on. Long live Jamal Edwards MBE, MBA, PHD.”