One of the other things that helped me is exposure therapy. I didn’t do it in therapy but I kinda had to do it when I joined the Marine Corps in bootcamp. Now of course joining the military isn’t the only way of exposing your self to stress, but there’s plenty of ways to do it. It helped me because if I can make it through boot camp with a stutter(which was absolutely horrible lol), than just having a conversation with a random person or just even a phone call feels like stepping over a ant hill when I’ve just previously climbed a mountain.