The trick is to never follow a specific set of words. I always had a hard time saying what people wanted me to say. The work-around is to mix it up everytime you have to say the same phrase. "Goodmorning how are you?" Can become, "hello and goodmorning is there anything I can do for you today?" Choose the path of least resistance. Take deep breathes and speak with your employer and tell them you have a hard time following scripts cause of your stammer and if its okay to just switch it up while still being professional and courteous. You got this. And if you stutter so what. My bestfriends still bug me about my stutter but its all in good fun. Dont take yourself and life so seriously. Stuttering is your unique trait. Just learn to work with it and itll actually come in handy when you say something dumb but your stutter stops you. And vice versa.