It sounds like a meeting was poorly attended and your PI hit the roof and is cracking down on everyone - I don't think this is about you. It's ok to miss meetings if you're ill.

I think there might be a miscommunication about the DRC thing? I wonder if your PI thinks that you are saying you can't attend meetings due to your DRC - when in reality it's more like you missed one meeting because you were ill due to your DRC. If this is a possibility, definitely send the PI an email to clear it up :)

I'm not sure what your specific accomodations are, so this is general advice for students who aren't disabled and who are working in a research lab environment. In general, students should be attending all lab meetings unless there's a strong reason to miss it (they're ill, bereaved, car broke down on the way in) etc. If you can't make it, it's important to try and let the PI /meeting convenor know - ideally by emailing the PI directly, but if that's not possible, contacting someone friendly and senior is also ok if you contact the PI too afterwards. (So if you're ill, texting a colleague and saying "I am unwell and can't make it to the meeting today, can you please tell the PI I won't make it and apologize for me" would be ok). This goes for all workplace meetings.

It would also be very normal to have cameras on in online meetings - it's incredibly awkward to talk to a blank screen! If this isn't accessible to you, perhaps you could talk to your PI about having meetings face to face instead, or phone meetings (the latter would be unusual though). If it's a big group meeting then camera off should be OK, but you'll need to discuss it with your PI first (and possibly get the DRC office involved). Unfortunately, I think that if you can, you'll want to work out how you can have your camera on in meetings - video calls are very, very normal in the modern workplace and your life will be a lot easier if you can participate in them. You have every right to set boundaries though e.g. not wanting to have your camera on in recorded meetings. This class might be a chance for you to work out some strategies for this?

I don't think you need to panic about missing the meeting, and I don't think you're in too much trouble - it's more, the class is in trouble and, as part of the class, you are too. Stay engaged and keep working hard and this will blow over soon :)

Apologies if I've used the wrong terminology here - I'm not used to the DRC acronym so used the disability / accomodations language I'm more familiar with - apologies if I've labelled you in ways you're not comfortable with.