Reading is very different than efforts at conversational speech. Reading aloud, like you said is much easier and without stammer or stutter. Why? I’ll stress again, that proper breathing patters do in fact, offer FLUENCY! If you can find something of high interest level to you that you wouldn’t lose interest or your concentration while reading, I encourage the initiation or induction of the Diaphragmatic Breathing while lying down in bed. Just the simple practicing a few nights before bedtime will make this method of breathing 2nd NATURE! Hold the reading material with your dominant hand, while lying flat on your BACK, then resting your non-dominant hand just below your Sternum & Xiphoid Process. The rise and fall of your belly is indicative you’ve initiated Diaphragmatic Breathing!