So, a lot of it is because of breathing? I fully agree! I think what you are describing is similar to costal breathing. There's an app for training that, called, similarly, keep it costal.I'm using it every morning and have seen sturdy improvement. It is also about gaining confidence, so speaking to strangers pushes your boundaries, which in turn makes you more relaxed and confident. That helps a lot as well. Some of what you are describing actually reminds of The McGuire program, which is also really helpful! And hey, kudos for this read, it was definitely something.