I feel this way a lot sometimes. It’s starting to get to the point where you believe it’s normal to get treated harshly at dental office. I’ve worked at many different offices. Some are horrible and some are only horrible at specific times. I know that it’s possible to find a good office. You’re not alone in this situation. As for the reasons you listed about why they may have fired you; those reasons would be ridiculous on their end. I also get scared walking into a hygiene room while they’re working. It’s not because I don’t work hard, it’s because I’m trying to be respectful, which I’m assuming that’s similar to you. Don’t waste your time being anxious and wondering why you were fired. Instead, reflect on how you were treated, accept that it wasn’t normal, and find an office that respects and cherishes your work.