Should i look for another job?

I work as a bank teller and I keep making mistakes. I try very hard not to but it still happens. I did' t relise that being a teller could be so stressful. For the most part I like my job and the people I work with but I'm really afraid I'm going to unintentionaly do something that causes someone to loose money or even get their identity stolen. And it's so easy as a teller to make a mistake or say the wrong thing to the wrong person. Should I try to get another job? I've lost sleep over worrying about something i've done at work. I don't like having this much responsibility over so many peoples livelihood.