The Frenchman has started the new season in fine form, helping the Gunners take five points from their opening three fixtures without conceding a goal.
However, the 26-year-old made just four appearances in the English top flight last term, all as a substitute, due to a number of injury concerns and he has admitted his struggles took a mental toll.
Diaby told Le Parisien: "Last season, before the Fulham game, I was shaking on the bench because I was scared of getting injured again. It was incredible.
|GUNNING DOWN THE SAINTS
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"I had some very difficult moments, some days when I was depressed when it was tough, but even then, I always kept faith. I always told myself that some people were in a worse position than me."
Following an impressive start to his return to action, the Paris-born midfielder has expressed his hope that he can continue to flourish.
"It is such an important season for me that I am working harder than ever to succeed," he added. "I want to prove to myself that I can go higher.
"I am getting to an age and to a time in my career where I need to show what I can do on the pitch in the long term."