These stories are a mixture of fiction and biography. Which is perhaps not the best way of sorting these things — but hey, life is never that neat.
The problem isn't that one is "made-up" and the other "real", all accounts of past events are stories and contain selectively fictionalised events.
I'm not a tape recorder. That's why we talk of "my life story": it's a selective, edited, and memory-filtered account of isolated events that you bring together into a constructed sense. (And you thought it was just some stuff you read. Shows what you know!)
No, the problem is that in biography, your responsibility is with the subject: its proper treatment, its forensic dissection. The story you tell with the pieces is a geographical exercise, mapping out the terrain of someone's life.
Fiction, on the other hand, has a responsibility to you, the reader: your engagement, your enjoyment; the satisfaction of your dramatic needs.
Given that both fiction and biography are constructed (as is documentary, film, photographs, news — indeed any media, no matter if it purports to be factual), the impact of these treatments is quite surprising.
I could of made this whole project, or at least the family part of it, purely autobiographical. But I'd of found that quite limiting. Put simply, I can't remember every time I got fucked.
To be honest, I even can't remember everybody I fucked, or even all their names. To have been only autobiographical would have been, in a sense, untruthful. With fiction I can fill-out some of the gaps that biography leaves behind, drawing on "truths" that can't be captured by assembling Just The Facts.
So if you feel that this collection, taken as a whole, doesn't quite gel, I think it's because of this mix of fictionalised stories and autobiographical accounts. But taken individually, there are many pieces I'm quite pleased with.