Sami Chokri says he was hurt by the tone of Sheeran's lawyers' emails after he noticed similarities between his song Oh Why and Sheeran's Shape Of You.
"I feel like I've been robbed by someone I respect, or respected," he told the court.
"This is years of a cloud over my head. All I heard and read was emails belittling me and my questions."
He continued: "All I wanted to do was ask for an explanation. If I'd had one we wouldn't have had to go through with this rubbish."
He later called the trial "the most horrible few weeks of my life".