Another thing that helps reading more slowly is reading out aloud. Imagine recording an audio book. I do that sometimes. It's somewhat soothing and also improves my pronounciation, which may seem like an irrelevant aspect but while my english is quite strong and I always read, listen to and watch english content in its original language, it's simply not my native language. Having the chance to read aloud/talk in english is a welcome and somewhat educational change.

Well, reading at half speed doesn't work for me... Either Like the book and do binge read or don't and I put it back and never finish it. Totally agree that a book is a different thing compared online.