I had to quit diving professionally after the Olympics. (Para.10)
Meaning: I had to give up diving as a professional job after the Olympics.
quit: stop (doing sth.) and leave
Steve quit when he realized that he could not win. 知道自己不能获胜，史蒂夫退出了比赛。
Others made critical comments about him because he quit his duties. 他因为放弃自己的责任而受到批评。