OM-doubted

Line: I doubted that I would ever come back Explanation: This line is saying that he went through the challenge, and he pushed himself, and he doubted that he would ever go back and take the easy road again.

Good observation! 

**doubt**
  [ dout ]  [|Use **doubted** in a Sentence]//**–verb (used with object)**//
 * < **1.** ||< to be uncertain about; consider questionable or unlikely; hesitate to believe. ||


 * < **2.** ||< to distrust. ||

//**–verb (used without object)**//
 * < **3.** ||< //Archaic// . to fear; be apprehensive about. ||
 * < **4.** ||< to be uncertain about something; be undecided in opinion or belief. ||