Most authors are embarrassed by their first book. I certainly was. But without that first book, you will never learn the lessons you might otherwise miss out on. So, put your work out there, fail early, and try again. This is the only way you get better. You have to practice, which means you have to keep writing.
Every writer started somewhere, and most of them started by squeezing their writing into the cracks of their daily lives. That’s how I began, and it may be where you begin, as well. The ones who make it are the ones who show up day after day. You can do the same.