I'm going to go on a limb here and guess that you are thinking too fast. In everyday life, try to slow down your speech and get in the habit of listening to yourself. It will help you be more deliberate with words and get into the habit of course correcting.
People have a tendency to talk lot faster than they think. Great speakers know how to control this just like how cars speed up or slow down depending on terrain.
I think speed variance is a good tool to have but I wouldn't purposely try to talk slower.
For example John Carmack is someone who I really enjoy listening to talk about any topic. It's like a pure uninterrupted stream of thought without filler words, often times for hours. Lots of folks say he talks too fast but I think his pacing is perfect, it's very engaging.
On the flip side, I'll get disengaged pretty quickly if someone is talking slow or uses a lot of words that feel like they've spoken 7 words to say 3 words of information. I think slowing down to focus on certain phrases is good in moderation but I don't think you should purposely try to turn a 10 minute conversation into a 15 minute conversation.