Anger Management (2003)

Mild-mannered timid businessman Dave Buznik works for a pet clothing company out of New York City. He's got an abrasive boss named Mr. Frank Head who frequently takes credit for his work and steps on him in return. He's got a loving girlfriend, Linda, whose best friend is her condescending college ex, Andrew. But when a misunderstanding aboard an airplane goes haywire, Dave is ordered by the court to undergo anger management therapy at the hands of specialist Dr. Buddy Rydell, who is an unpredictable, psychopathic character. As the relationship between Dave and Buddy becomes more tense, when the unorthodox treatment wreaks havoc Dave's life, and Buddy might be the only one who can save him from a problem he recognizes right away in his patient, that could only get worse.