I didn't tell a single member of my family, nor any of my friends, that I was writing a book. I didn't say a word about it to anyone, in fact, until it was published. Now I self-publish, and I still find it difficult to talk about my current projects. I'm used to going it alone, but I've learned that it's the absolute worst way to go about writing.
Unsupported
Writing anything is difficult. Writing a book is an exercise in self-torture. And writing a good book takes more than what you currently have inside of you. If you're going to write something great, you're going to need other people in your life to help you get through it. At the very lest, you're going to need someone who can remind you to eat something every once in a while.