I'm 32. When I was 17, I got a job working rides at Six Flags. I was working in a position where I was forced to talk to thousands of people a day. Eventually, I was promoted to the position that speaks on the microphone. I was nervous as shit too lol. I struggled a couple of times, but once I got it down, it felt amazing. I even started getting compliments on my voice. Maybe you can get a job where you HAVE to talk to people, and it'll give you the practice you need to find out what works for you. Now that I'm older, I started talking very slowly. I choose my words carefully and I don't rush and try to force a sentence out like a normal person. Sometimes, it takes a curse word for me to spit something out lol, but it's what I learned works for me. You'll find out what works for you.