So what do you call your father? Do you really interpret that so literally? What about Paul calling himself father to many of his churches? You just ignore that?
Father "in the gospel" Paul says, his appeal is simple, for other apostles had followed up his mission preaching against him, claiming to be superior to him and preaching a truer gospel which was a false gospel.
But they had received salvation through Paul's gospel...the Holy Spirit was working in their midst through his gospel. ...Paul didn't even begrudge that some favoured Cephas or Apollos, he said "ye may have many teachers but I was the one who first brought you the gospel"
That was his point, in the sense that he first brought them the gospel he was their father in the gospel. But Paul did not seek to lord it over them...they stood in their own faith.