Inattentive here, and I do the same thing sometimes. The most helpful things for me are:
1) in normal conversation, don’t worry about it. No one cares. If they do, they can pound sand.
2) in a presentation/storytelling setting, plan out what you’re going to say beforehand and practice.
Some things that helped me that I don’t think are as globally relevant:
record your voice and get used to how it sounds. Try mimicking voices and intonations and see how that changes how you sound on the recordings.
Practice speaking mindfully… say each word and follow it out with your mind. Try to gently redirect your thoughts back down to just speaking with when you drift.