Reading slowly is questionable advice. You should get a different therapist. One thing you may want to practice is what is called gentle onsets. And the technique is a little different depending on what the starting sound is. Some sounds are very easy to do this with. For example, with an "m" or an "n" or an "r", really anything you can sort of stretch, start out with a soft humm to prime your vocal cords, and then the rest of the word will come out. No matter how bad your stutter, you can always hum, so that is one trick. It does not work on all sounds, as it is harder to stretch a "d" for example.