Here is a quick tip to help you with your fear of public speaking. Many of you may have that.
It is an increasing trend that I have noticed these days that nobody likes to leave voice messages. Now, if you think that in that particular situation, you are better off leaving a text, then it is alright. But if you are going to take the time to call someone, then make sure that you leave a voicemail message as it is a type of speaking.
Now, leaving a voice message is not public in the sense of thousand people watching you but it still tends to make people nervous. So, what I recommend is that focus on one thing, leave a short and simple message, and then listen to it. Most voicemail gives you the option of listening to your recorded message. Listen to it once, and then if you are not happy about it, redo it one more time.
Do this a couple of times a week, and it is a type of speaking. You get used to hearing your voice, you get used to making improvements, and overtime, it will contribute to building your confidence. So, make it a habit of leaving messages and listening to them occasionally.