I stutter when going on a date and when communicate with people higher status than me

I stutter when going on a date and when communicate with people higher status than me First time poster here. I'm 21 yr old male.I'm working on my body,Journaling,not smoking or drinking and have a very healthy life except I'm working three shift for more that 2 years and my sleep schedule is bad (I will change my job soon). When I go on a date I stutter , sometimes is more , sometimes with other girls is less.I think problem is when I'm overthinking I stutter , but when I'm calm I don't have that problem. My question is , how to be calm when I'm on a date with girls or when communicate with people higher status than me? How to reduce my thoughts and stop overthinking? Thanks