Short answer. It didn't.
That sounds harsh, and maybe it's overstating it a bit; it did change my life and in some quite pleasant ways. Now, for example, I am a published author. I couldn't say that before. I've also done things that come with being a published author - I've spoken about and read from my work in public, seen my work on library shelves and bookstores, autographed copies for readers, even heard people tell me how much they liked the book - followed with the inevitable, "When's the next one coming out?"
All of that was, and is, wonderful.
But if I thought publishing a book was a door into a magic kingdom where I would never be uncertain about myself, where the struggle to gain recognition would be over, where prose would flow from my fingertips like water from a busted main, where a halo of fame would follow me like I was lit from inside, making all who saw me shudder with pleasure at my approach... None of that happened to me, and it probably won't happen to you.
If you're writing because you want to write, and because you're only happy when you are writing, because there's a story bubbling to the surface inside you, a story that you know only you can tell - then you're on the right track. If the only thing that keeps you going is imagination some perfect world of fame and wealth on the other side of that first published title, then you're in it for the wrong reasons, and you're only going to wind up disappointed. The second type of writer is hoping that publishing will bring him the love of strangers. It won't.
Don't misunderstand me. My life is wonderful, and writing is part of what makes it so. I get satisfaction from writing, even joy. Publication is the imprimatur that says my writing is worthwhile to others, and I eagerly look forward to my next book. But nothing will make the job of writing automatic and effortless, and I would lose interest if it did. But I don't expect love from my first book, my second, or my thirty-first. Love I get from my own darling wife, my children, my friends.