It sounds like you may be experiencing speech blocks? I was taught when this happens to take a pause and begin to quietly hum or whisper the begging letter of the word to elongate the sound and get it out if that makes sense. It’s not noticeable if you’re speaking at a slower pace but it can be awkward if you’re speaking very fast then suddenly say a word extremely slowly. People with speech impediments should be speaking at a slower place anyways!