You wrote that you "recall" hearing about the Gospel of Q.I have talked about Q from the start.
What you are "recalling" is recollections of reading my posts about Q, which date back years. I first heard about Q and other pre-Gospel written sources from Bart Ehrman and Luke Timothy Johson.
Let's face facts: the standard atheist argument is, and always has been, that nobody wrote anything about Jesus until 60 or 70 years after he was dead. Which atheists always cite as "evidence" a historical Jesus either may not have existed, or that most of the stories about him were later fabrications.