If I'm alone and read loud for myself, I speak fluently. I guess the reason is simply, you don't have to worry. You don't feel in a hurry to say something. No worries what they might think. How you look etc. All the avoiding strategies are also not very helpful and make it more difficult. I can only recommend to take all the time you need. Focus on the sound of my words, keep eye contact and keep breathing helped me tremendously