Serious blog, I need to vent

I had an incident at work, going to try to type this out without crying, because I finally calmed down enough to stop. So background for anyone who doesn't know, I'm a barista, I work at a coffee shop in an office building. I'm a supervisor, and I've been there 4 and a half years. So I was supposed to work 9-530 today, that's my closing shift that I do several times a week. I started at 9, and things seemed totally normal to me. There are 2 other supervisors who were there too. At one point the male one was pouring some lemonade into a clean container, but the female one thought he was putting it in the dirty one next to it, and she went to correct him then was like oh "nevermind." And I said to him as a joke "wow she was just so eager to scold you." Then like a half hour later my boss told me she wanted to talk to me, so she takes me into the office and closes the door and says she needs to talk to me about my behavior and how my negativity makes people uncomfortable and I make people feel stupid, etc. Because apparently they were both just DISTRAUGHT by how harsh my comment regarding lemonadegate was, and like... I'm legitimately baffled. Like I DO have a lot of moments where I think I'm smarter than everyone, and I occasionally say something snarky that might come off as meaner than I intended, I have a lot of compulsive issues and that's one of the things I've been working on in therapy. But this really wasn't one of those incidents, and the whole thing left me confused. And then my boss kept going on about how apparently those two have been complaining about me a lot and they "don't feel supported by me" which I really don't understand, if anything those two are constantly off talking together and leaving me out of communications. This went on for awhile, at one point the female supervisor came in, and she was like...stating her case calmy but it was so baffling, because this woman is a proud self proclaimed bitch, and she often says things harshly to the baristas, but apparently my saying things like "wow she just loves to scold people" in a jokey tone makes her go home and cry about how mean I am. She also claimed I never say anything nice and I KNOW that's literally not true. So anyway I'm like really upset and crying at this point and I'm supposed to go back out there and work 7 more hours and run the shift, and I just couldn't do it. So I said "I am going to take a personal day, I will see you all tomorrow." Then I walked out of the office, clocked out, gathered my things, and left. I might get in trouble for leaving, like a write up for an unexcused absence, but they can't do anything about it, it would be my first one ever and I know there's a process with HR. BTW, my boss's boss was in there for all of this. He likes me and knows how hard I work. He didn't say much during the conversation at all, but I don't think he was against me in it. I'm just like so upset. I have an insane work ethic, I work so hard, I make sure everything is done perfectly before I leave when I close, I'm constantly cleaning up other people's messes, etc. I'm not saying I'm perfect, but I don't understand what my boss thought she would accomplish by having this conversation an hour into my shift (she knows I have mental health issues too). Like did she really think I would be able to smile and say I will be perfect and then calmly finish my shift? Anyway, since I'm so unsupportive, they can see what unsupportive is like when one of them has to stay and close the store today.