My experience probably won’t be helpful to you, but here it is. I’ve written 2 eBooks, but really I only wrote hundreds of very short illustrated stories. And then compiled them into 2 books and published them on Kindle. And did very little promotion. So, they’re there but I’ve sold very few copies.
The thing is, I only write what pours out of me, so I don’t struggle writing. Mine is neither a success story or a tragedy. Or an inspiration.