When you read, your brain focus on reading. When you not read, you think words. Reading out loud can help, but only if you hear fluency and don't hear dysfluency. There are more to it, but as of "exercises", you should practice to speak immediately. Just speak, say anything, but not the words you are thinking. You cannot hesitate or have any pauses. This needs a lot of practice but many can beat this in just some months if they work hard.