You are right, Jesus didn’t write any of the Bible, but were it not for the Bible, we would know nothing about Him.
Thus Sola Scriptura.
For the record, I am questioning Sola Scriptura as well as Sola Fide myself and may be leaving the Lutheran church, but having said that, and even if I do leave, I hope I will retain some recollection of what Protestants actually believe rather than embracing and repeating the caricatures of Catholic ePologists.
This is not directed to the author of the OP specifically. His question does betray a lack of understanding about what Sola Scriptura really is but I have no idea whether he was ever Protestant or not. I am merely pointing out a phenomenon I see all the time around here: The persistence of Catholics in misrepresenting Protestant doctrine IN THE VERY TEETH of better representations given by ACTUAL Protestants.