You need to do some practice at home first. But eventually, you will build up to this - before speaking, make eye contact with listener, begin slowly on a small *exhale* (breath *out*). Regarding stopping your brain, that’s soooi hard! Try noticing your surroundings. Count your breaths. Take longer exhales (scientifically proven to be calming). Sounds like you are ready to do the hard work. Check out my profile to see my recent post with other ideas and links. It’s all free, and comes from folks with the proper formal training. Let me know if you have questions :)