Oh yeah, I know I probably have that problem too because I totally rely on saying “umm” or “mmm” “uhh” every time before I speak, however I personally feel that’s the only way I can somewhat get through speaking daily. But honestly most of the time lately If I start stuttering when talking to someone or in my classes or on the phone, I’ll pause and say something like “damn I can’t speak today!” Or “sorry I’m struggling this morning!” And then just move on. Honestly I’ve just learned to try my best to avoid the sounds I know I’ll have trouble with, and that’s helped!