Sorry to crush your sweatpants-and-chill spirit, but the most common advice for avoiding falling asleep while reading is to not read in bed. If you want to get technical, the best reading position, scientifically, is to sit in a chair with your book in front of you, preferably at a desk. Good posture and quality ergonomics are your best friend, even if your bed is calling your name.
Source: https://www.distractify.com/p/why-does-reading-make-me-sleepy