The Japanese full-back struggled for gametime in an injury-hit campaign, which ended prematurely with only six Premier League starts to his name.
Ben White impressed after being moved over to right-back by Mikel Arteta while Tomiyasu was guilty of a notable error in February’s defeat to Manchester City when filling in for the England international.
“It was a difficult period for me,” he admitted to football.london.
“Ben White was doing very well and to be honest I lost confidence. But the injured period was four months and I thought about a lot of things at this time.
“You need to learn from the injuries, also the mistakes from the Manchester City game as well. You have good and bad moments but you need to learn a lot of things from the bad moments.
“Now I am feeling good, not only for the body, but my head and also my career. It’s all positive.”
Tomiyasu, 24, also has additional competition for his place this season in new signing Jurrien Timber and he’s determined to prove himself on the training ground before expecting to earn a spot in Arsenal’s line-up.
“I am so excited to play,” he continued.
“But the only thing I can do, I just want to be on the pitch to help the team. So the first thing I need to do is prove my value in the training.”