After the book is published, it's out of our hands. Who reads it, what they say about it, whether readers recommend it to other readers, is completely out of the writers control. This is both terrifying and liberating (for me). The control I had while writing and editing my book is no longer mine, which, in a way, lets me focus on the next book.
IMO, after your work is published, always focus on the next book. It takes away the anxiety and lets you have control again. If you want wider readership, focus on selling the next book to a bigger publisher with a strong marketing department and better distribution. Sometimes it takes a successful book or two before an agent is able to get the next book into the hands of one of the biggies. But that's what I'm hoping for. Some day.
We can't rush it and some of this is not under our control. What you can control is writing a kick-ass book, and I think you now know that you CAN DO THAT.
GL, my friend. xo