Tongue slip problem in presentation even after a good amount of practice
Years ago, I transcribed raw film footage to earn a little extra money. These transcriptions had to be verbatim, with all the ums, ahs, stuttering, etc. included. It's surprisingly difficult to do a verbatim transcription, because there is a strong tendency for listeners to hear what is meant, rather than what is actually said. We transcribers had to listen to things three or four times to record the speech exactly. The first time I listened to something, I wouldn't even notice the mistakes!

Some of the transcriptions I did were of people famous for being well-spoken, people I admire very much. I was surprised to learn that they make frequent speech errors/hesitations/disfluencies, just like the rest of us.

As a result of that experience, I realised that while we are all painfully aware of the imperfections in our own speech, others hardly notice them at all. Most mistakes are filtered out by the listener's brain, and aren't truly "heard".