I can never make phone calls

I can never make phone calls I’ve had stutter my entire life, but it gets significantly worse when I’m anxious and having to make phone calls for an appointment (or really for anything) is one of the main sources of anxiety for me. I have been wanting/needing to see a dentist for a long time but I have been putting it off and putting it off for months because of the fear that I won’t be able to get through a sentence without stuttering and worrying about embarrassing myself. If anyone has any tips or tricks about how to get over this I would really appreciate it.