So often in writing, we get pulled by the words or by the characters or some other exciting part of the process. However, the reason readers are going to keep coming back to pick that book up again is for the actual story, the drama and the high stakes to get to the end.
A lot of writers worry about the future because no one knows how well the next book will sell. Keep your eyes on the page. That's where all your opportunities wait, where all your happiness and interest and pleasure waits.