Hey Julie, I also double space after a sentence and I'm not yet 40 😄
Thanks for being so honest about your fears along the journey. And for the useful websites and software you used, and the people who helped. It makes the process look easy. Did you at some point consider hiring an agent ?
And to answer your question, I have the same fear that no one will read my work... if I ever get to publishing a book, I will need some help marketing it.
Glad you have made it and are now reaping money from your efforts and knowledge!