My Brother, Who's a Perfect Human Being, Has Stolen My Girlfriend and My Future, so I Went Back to the Past and Redo My Youth

In spring at the age of 26, after 10 years of dating since 2nd year of high school, I proposed to her. Her reply was that she would marry my younger brother instead of me. My younger brother, who’s a perfect human being and the complete opposite of me, has been having an affair with my girlfriend for the past 10 years.In despair over such a life-altering event, I threw the ring into the sea. Then somehow, time has brought me back to my 2nd year of high school, 10 years before I started dating her !Having returned to the past, I will take revenge on my brother and my girlfriend who betrayed me, and start a new life !