Asked to stay late at work

Hey guys, I'm feeling a bit down right now and I really need to talk about it lol. Every summer since I've started college I work in the same supermarket (it's my 6th summer working there now, I got my master's degree last year but decided to travel so I came back home with no money haha hopefully I should be starting a new job in September but I'm still waiting for the confirmation from the company). So, I've started work yesterday and I was supposed to go to the click and collect section of the shop but they needed help with the stocktake so they sent me in the storeroom to count stuff (mainly toys). The whole place is a complete mess, and yesterday I was left alone doing something completely new which kind of pissed me off 'cause I was like 'okay where do I start, what do I do'... But anyway, this morning I got there at 6 and was supposed to leave at 1pm but since my colleague was alone, I told her I could stay until 2. The manager (I think he's a manager, no idea lol, but I've always hated this guy) said that it wasn't worth it, but that I could go home, get lunch and come back, which I clearly didn't want to do, I work at 6 again tomorrow and I didn't feel like it at all... So he asked me "Can you come back and stay?" And omg of course I could stay but I just really didn't want to lol. I was so pissed at the way he asked, it's not "do you want to stay" but "can you" so I got angry and I said "well yes I can", which made him and my colleague changed their minds I guess 😭 They saw that I was kind of angry and told me that I didn't have to and that it was okay. So I left and I feel so bad, first of all for leaving my co-worker but for not being able to handle working a bit more, to push through the fatigue. Now that I mention it, I had no reason to feel pissed at all in the end and I wish I had stayed. I don't know what happened for them to be so behind with the stocktake though, they were supposed to finish it by June 30th and they had until today to catch up. Anyway, I just needed to vent, I don't expect a particular reply. All I know is that I really don't want to go to work tomorrow :') It's been hard coming back and I'm really struggling with my mental health, so this really isn't helping, I don't mention it because I already sound like a gen z cliché who doesn't want to go to work lol. Alright, thanks for reading! (English is not my first language so please don't be too mean hehe :'))