Hey ik that feeling on the phone where you literally cannot say a single word, and it is even worse then with talking face to face. I might go a little deep here but, what are you going to do if your parents are not there to help you out one day. I feels weird for me to talk about all those stuff even tho I am sure I am younger than you but ya. You need to start talking baby steps and taking the responsibility for yourself. Cause when they are gonna get a sudden surge of stress and anxiety when they are not able to make the phone calls for you, that would not be a good feeling. Idk if you have tried speech therapy or not but I do think it helps with all interactions. Just wanted to give a word for your story.