I am currently working part-time at a café on weekends, putting in 3 hours each day. Unfortunately, I've been struggling with back and knee issues for nearly three years, which have worsened recently. I suspect I might have a microfracture in my shin, but the doctors haven't confirmed it with an MRI yet. After taking a two-week break, I returned to work today but found myself in pain again. I’ve been feeling really frustrated and disappointed in myself for not being able to handle such a small workload. I was supposed to tell my manager that I’m quitting today, but I just couldn’t bring myself to do it. I plan to talk to her tomorrow, but I'm anxious about how to approach the conversation, especially since the café is usually busy. I want to say it face-to-face rather than through a text, but I’m not sure how to start the conversation.