Conversely, Romero's father has believed that "he [Romero's father]’s the reason why  I made it so far"—that "he’s the one who gave me  all the inspiration behind my career" but Romero believes that his father is mistaken.
The passage presents a contrasting perspective on the role of Romero's father in his success.  Romero disagrees with his father's belief that he is solely responsible for his achievements.