I suffer from the exact same thing. It's so common for people to ask me to repeat myself.
Also, I feel like my voice is very monotone. It's not very expressive. My nephew one time commented that I sound like a robot lol.
I don't know if it helps, but I've been practicing reading out loud to a voice recorder, then playing it back, taking note of what words or inflections I need to work on to sound more normal, clear, and alive, and repeating them again and again till I sound ok.
Doing the same might work for you.