How to controll stuttering when working like a waiter or similar...

How to controll stuttering when working like a waiter or similar... Hello everybody, At young age from maybe age of 8 I started stuttering, at age of 14 let's say I fixed it 80 percent. But when I would work as a waiter for example or some job where I need to communicate with people, I get a problem. For example it's not a problem when somebody asks me what is a price of Coca Cola, becuase I know it... But when I need to say something that is not "learned" I get a problem. For example, when somebody would sit at some table which is previously reservated I feel like a get a problem because I get nervous. ​ So is there any tehnique for blocking nervousness (instead of getting drunk or high XD)