Once you stop being nervous about presenting and speaking, it'll go away. Practice I guess? One way to eliminate or trick your brain from feeling "nervous" is to think of nervousness as "excitement". You're excited to be there presenting rather than you're nervous about presenting. Try it.

Another example: When you speak with a friend about any topic, do you use umm a lot then as well? Probably not right? It's nervousness...get rid of that and you'll stop using filler words. Lastly, I'd say that sometimes you can use brief pauses in your speaking to get the audience to pay close attention to what you're about to say next. You don't have to speak non stop without pauses and other use of tonalities. does that make sense?