It's actually not that hard to speak text fluently. You need to practice, but only a little. The trick is to speak a little slower than you read, and pre-emptiv

It's actually not that hard to speak text fluently. You need to practice, but only a little. The trick is to speak a little slower than you read, and pre-emptively flick your eyes to the right, skimming the oncoming text, so you have a buffer of context in your mind. Pause a little more at sentence boundaries; this gives you more headroom and makes you sound more refined. The idea isn't to fully process the future text, but to get a rough sense of where it's going -- a question, a subordinate clause, a list, etc -- so you can adjust your intonation in advance. As an experiment I spoke your comment aloud as I read it. It sounded natural and I made no mistakes at all.