Overthinking when talking

I tend to overthink when I talk, which leads to me jumbling my words because I’m trying to find the best word to use, so that my audience will understand my point and what I’m trying to communicate. My overthinking also leads to a monotonous and slow rate of speech as well as a lack of eye contact (looking away to think), which doesn’t make for engaging communication. I’m not sure if this is typical for an introvert or if anyone else experiences the same but any advice would be appreciated!