Something I've found to be exceptionally good at helping with reading (I've been reading ~50 books a year for the past 5 years, on top of a full time job and family) is to use Goodreads - it gives you those short term endorphins when you can mark a book as read and can help it compete with all the other offerings of the world that reward you more hormonally.

Alternatively, if you don't want to use the tool, I would recommend getting a nice notepad to write in some short book reviews, which will give you your endorphins as you fill the book up more. And you get the additional benefit of being able to look back through your notes to see what you thought of various books and how your thought x time ago.