If you are a self-published author I suspect you write for two reasons. The first reason is that you enjoy writing. You enjoy it because you feel you have a voice that contribute to the universe in some unique manner. The second reason is that you want other people to read what wrote. You want this because it makes you feel good about yourself. It reaffirms in some way that your work is unique and worth reading.
You might say that the first motive is purely based. That is, the experience of writing and creating is its own reward. It generates the feeling of well being and accomplishment. Perhaps there is no separation between creating and the feelings they seem to generate. It is all one non-dual process.
It seems that the second motivation is less pure and ego oriented. That is, when other people read and react to your writing it gratifies your ego. It reaffirms your sense of self and your worth as a distinct identity. Please understand, I do not make this distinction out of a sense of judgment. I am basing this observation on my own perceived motivations and projecting them on to everyone else. So even if there is a hint of judgment in what I have written thus far I am equally judging myself.
After all, what is wrong for an author or the creator of any piece of art to want other people to appreciate their creation (and by extension themselves)? The purpose of writing is for people to read it. But even this purpose could have dual motivations behind it. For example, the author might want another person to read their writing purely because the writing conveys information or beauty that the author wants the reader to experience for him or herself. On the other hand, the author might enjoy the fact that other people are reading his or her work for ego purposes.
I suppose one might say that writing and the motivations behind it is a complex dynamic. If we are being honest as authors all these motivations exist to greater or lesser extents, depending on the situation in some mysterious combination. There is the sense that to over analyze the process depletes the creative flow of the whole thing. But there is also the sense that to appreciate the complexity and mysteriousness of the process is a worthy meditation in its own right.
Either way, keep writing.