If your speech therapist is not a good fit ...

Jennifer Bekins' blog post might help you to work through the sometimes difficult process of recognising when therapy is not going well, and a change of personnel might be a solution. Of course it's okay to take a break, too, or just to stop if that will work better for your child and family - sometimes we just need someone else to point it out, or reinforce the conclusions we've reached ourselves:

Changing Therapists
Jennifer Bekins, Talk - Down Syndrome, 6th February 2015

... I’ve had a number of people ask me recently, “How do I know if it’s time to change therapists?” 

This is a loaded question with lots to consider. I’m going to base the initial question of switching therapists on the assumption: There is someone your child can switch to ... It’s okay to change.