Can someone help me rationalize my anxiety? :(

19f and diagnosed with GAD when I was 14. I found out through one of my work friends that my store manager is closing the store we work at tonight… This is only such a big deal to me because in December I had an anxiety attack going into work and I had to leave so when I called her to let her know she was furious with me and wouldn’t even let me try to explain myself. It was so bad that I started crying on the phone and then she just hung up on me. I never got to explain that I was anxious and that’s why I had to leave. Long story short I was supposed to be the opener but the doors were locked and it was 5:45am so it was dark outside and I was panicking about being alone in the lobby. I since realize that I made a mistake and I should’ve just stayed. But after that instance with her yelling at me I just feel so nervous around her. Tonight me and my work friend are scheduled together but he is leaving at 10:30 and I’m there until we close at 11:30… So I’ll have to be alone with her for an hour. I’m just super nervous I’m going to be yelled at or I’m going to make a mistake. I know I should just be professional and not let my anxiety get in the way but I haven’t really seen her since that incident and I’m so scared. Can someone give me some advice on how to overcome my anxiety and get through this despite the fear and awkwardness that I’m anticipating?