I don't know if a more paced narrator would help, but Davina Porter and Scott Brick are clear, enunciate well, and have a pretty steady pace. There are others, but my brain can't hold that catalog.

If you have audible, read the reviews. Somebody always reviews the narrators. See what they say.

There are a ton of great ones. I pointed out these two specifically as they have a lot of material to choose from, and with a stable voice, it might be a bit easier on you.