TTTC as an artifact and outside literary references

In the chapter "Notes" O'Brien throws a serious curve ball by explaining his reasons for writing The Things They Carried. The reason it's so confusing is because O'Brien is clearly calling attention to The Things They Carried as a fictional work, but at the same time, we're left uncertain if the narrator of this chapter is Author Tim O'Brien or Fictional Tim O'Brien. As I said before, both are authors. Both have published "If I Die in a Combat Zone" and "Going After Cacciato". So which Tim are we listening to as we read this? Is this an interjection from the author or another fictitious element of the novel?

The author also says, several times in several chapters, "I'm 43 and a writer now", calling attention to his role as a story teller, while simultaneously making us wonder which Tim O'Brien we're dealing with.

O'Brien also references his other works several times throughout the book. First,  Fictional Tim O'Brien acknowledges that he authored the novels "If I Die in a Combat Zone" and "Going After Cacciato". Also, in the final chapter of the book, O'Brien references a story in which a soldier named Stink Harris, originally a character from "Going After Cacciato", wakes up screaming to a leech on his tongue. There is also an exchange between O'Brien and Alpha Company's Norm Bowker in which Norm comments on serving as inspiration for a character in "Going After Cacciato", despite the fact that Norm was fictitiously created by Author Tim O'Brien almost a decade after "Going After Cacciato" was published (or so we think).