So the part that's hard is not reading from the Chumash (do you use large print?) but from the Torah itself, which obviously can't be altered in any way and still be a scroll.

There must, at this point, be dyslexia-friendly study books with the Torah script on one side and the annotated text on the other. You would not be the first one to chant slowly enough to move the pointer along the Torah while following the printed book.

This is the system my workplace uses, in fact, Marion was our Hebrew reading specialist till health issues forced her to retire. http://www.cantoreducator.com/forsale/hiaf/