Somewhere or other I came across a link to a site called Overnight Success. Here you can find some 40+ writers telling you how they came to write and sell their first book.
Some of these stories are definitely more interesting than others; and all seem to be on the short side. The site is a joint production of Mystery Ink and the Crime Fiction dossier, and so most of the writers are in the crime/thriller genres. Also, most seem to be American.
David Morrell tells how he went the classic literary route at first, writing literary short stories and obtaining a doctorate in American literature at Penn State. After that he taught at the University of Iowa (?creative writing or Eng. Lit.). And then after that he wrote the first Rambo book! Well, I guess somewhere along the line he realised that literary short stories were not going to pay the mortgage. He has churned out some 25 books since.
One or two of the author's accounts are not very interesting at all, I'm afraid. Perhaps the process of recalling that early struggle was just too painful.
And if you really think life is giving you a hard time you might read Robert Ward's story: he nearly got lynched in reverse, as it were.