I used to work retail, and I struggle enormously with social anxiety. What I found helpful was having a set script for customer interactions. If it did not go well, then I could call in a manager or something, but it at least minimized the stress a little bit. I don't know exactly what your job entails, but mine entailed selling and making coffees. So people could be a bit uptight. But there were also really awesome customers too. So perhaps that might help ease your stress a bit. The best thing for me also was to just keep reminding myself that I am awesome. It might sound egotistical, but just to keep reminding yourself that you are enough and you are important, is so helpful, I believe, at least it has been in my own case.