Honestly, this sounds like a reasonable response and I don't think you did anything wrong. It's unprofessional for your superiors or teammates to blame stuff on you that's not your fault. I've had a similar experience and it's not enjoyable, especially because once you get blamed for something it can be hard to regain the lost confidence of others for being the person who "broke the feature" (even if you didn't break it). You need to take responsibility for mistakes you make, but also push back when people blame you for things that you had no part in. If a meeting devolves into "let's blame Progs for all the mistakes", it's perfectly reasonable to walk out of such a hostile environment (after saying your peace about how it wan't your fault and trying to recover your reputation). Such an experience is not a meeting, it's an attack, and it's reasonable and acceptable to remove yourself from such a situation.
Now, the question is, when you return to the office, what sort of environment are you returning to? This is an environment which has burned you, by blaming you for things you had no part in, and expecting you to fix a list of bugs that have been years in the making. If it was me, here's what I would do:
Schedule a meeting with your manager ASAP. Calmly, and with as much evidence as possible, explain to them what the issues are that caused whatever it was to break, and explain what the root causes are and how they are not your fault. Get your manager on board with the fact that these are not your fault, and while you will do your best to fix them, getting the blame for them in a public meeting is not fair and it made you (rightfully) upset. Ensure that your manager will back you on this (that these mistakes are not your direct fault, even if they are your responsibility to fix) and help clear your reputation with the other attendees of the meeting.
Explain to your manager the complexity and difficulties in fixing the other bugs he assigned to you and why they will take time to fix. Show him your system-level expertise by explaining to him all the things you do not know and will have to learn to fix these bugs. Paradoxically, explaining things you do not know is often a great indicator for how much you do know; if you say "there's a lot of stuff I don't know", that means you don't even know what it is you don't know. If you say "I don't know X, Y, Z, W, Q systems and I have to learn them all before I can even start on this" that means you know what those systems are and that they have some impact in the issue at hand, which shows a great deal of knowledge about the system even though it sounds like there's a lot you don't know; there's a lot you don't know, but also a lot you do know, and that's important. Get your manager on board with the fact that these bugs aren't a simple fix that can be rolled out in a couple weeks and will take some manpower to deal with. Then it becomes his responsibility on whether to deal with it properly or not.
Try having this meeting with your manager and see how they respond. Don't get angry, don't even get even. Just present facts, without emotion or bias, and let your manager respond.
If your manager responds well, e.g. if they apologize for blaming you, accept and understand your timeline for fixing the bugs, etc, then the book is closed and continue doing your work as normal. Keep this situation in the back of your mind in case it happens again (this could be an indicator of a toxic work environment), but for now leave it behind you. Conversely, if your manager tried arguing back to you and defending blaming you in the meeting, or goes off on you about how you don't work "fast enough" or whatever, that means you don't have respect in this company and it's time to find a new one. If your manager does not respond in kind to you, calmly and amicably and without laying blame, trying to resolve the situation, then it's time to find another job because this one is too toxic.
the company boss a lot more unprofessional
- This is not an excuse. Don't mention this in any discussions about the situation. Accept responsibility for your part in it, and acknowledge further action items that are needed. Focus only on the things that you can control for yourself.