I know i can talk fluently so why i struggle

I know i can talk fluently so why i struggle So as my title says, I’m feeling very frustrated because of my stutter . Basically I graduated university some months ago , and I’ve been in the stressful journey of looking for my first big girl job. The thing is that everytime I have an interview I stutter like crazy , I usually start well but the moment I have to talk about myself I always block ( I do better in in person interviews). Recently I started working for this restaurant as a waitress ( I’m still looking for a job in the sector I studied in) and it’s the kind of job that requires A LOT of talking . I found myself talking very fluently with everyone, I even talk to the phone with clients fluently ( which was surprising since I usually block during phone calls) , this is giving me a lot of confidence tbh because it means that I am capable of talking without blocking or stuttering. I really don’t know what to do , cause I really want to find a job in my field of studies but I struggle every time during the interview. Does someone of you have experienced the same thing? And how can I be better during interviews ? Thanks