Arnautovic joined Werder from FC Twente last summer but the 22-year-old struggled for form, scoring just three times in 25 appearances, and was also involved in a nightclub brawl which saw him suspended by the club in May.
He admits he has failed to justify his 6.2million euro fee and has pledged to work harder.
He told Kicker magazine: "Much has been written about me but I provided the stories.
"It was clearly my fault and I want to change.
"It is a new season and I can feel the confidence from the club, the coach and the general manager. I just want to start over again.
"A year ago I said that we would be champions, I'll hold myself back this time."
Werder flirted with relegation last season before eventually finishing 13th.
Austria international Arnautovic predicts they will not be among the struggling teams in 2011-12.
"We have too much quality for that," he said.