You are totally right it is much easier said than done. And everyone's approach to it is different. When I was in speech therapy we did a lot of live practicing. Literally call actual places and ask basic questions about normal stuff. Call a pizza joint ask for their prices of their pizzas. Call a music shop and ask if they had a particular instrument in stock. The point was it was low stakes. If I stuttered the person couldn't see me, I couldn't see them, they didn't know me, nor I them. It was pure audio based communication and then allowed me to focus a bit more on how to speak smoother. To this day I sort of flex on that energy. The drive through person at mcds does not give a fleeting fuck how I speak and thus it takes some weight off my mind. Boom one more way to practice speaking as smoothly as I can. And then when I am in a situation where I'm talking to a client or a store owner or my boss I can be like "I've been here before use that energy." And you know some days I bomb and some days it's all good. Its how it goes. And I get it if it ruins your day, that's understandable. I've had ruined days because of it. Its not fun. And all I can say to that is as the good days start to outnumber the bad days, it's easier to get over a bad day. Good days can come when you move another inch out of your comfort zone. Even if it doesn't go how you hoped. But those really good days come when you order starbucks and just pop off an order without any stalls or blocks. And I swear the first sip of that drink tastes better for no other reason than you ordered it without anybody even batting an eye at how you spoke. This is all comes down to mental approach imo. And I don't mean to say "just change your thinking" because that's not really helpful. But this approach helped me climb a few mountains and come out of a few dark places.