Probably controversial on my next few words but use your phone as an ereader.
Go through a couple of apps for ebooks (FDroid as a few) until you find the app that most suits your needs.
Amazon is not your friend, so try to explore other venues; Smashwords has a pretty interesting catalog. Project Guttenberg has a good number of older texts and public domain books, all for free.
I am sure other options exist, especially if willing to navigate the high seas.