You know what Sequins, I really hope that you and your kids manage to have a good Christmas after all this totally unnecessary and hypocritical crap.
We can argue till the cows come home about your so-called 'irresponsibility' in having any alcohol at all blah blah blah, and whether or not you were affected by a bug (sounds likely), whether you were sufficiently apologetic and so on. But the thing is, you're human and if you made an error of judgement somewhere along the line of your night out and its aftermath then so bloody what. None of us are perfect, we all do things which, with hindsight we realise we could have done better/differently. It's hardly a hanging crime - I see nothing in what you've described as malicious intent for example.
Anyway, that's not the point (for me). Regardless of your parents' annoyance (understandable, to a point) the way they handled it was disgusting with your kids within listening distance. Now that is appallingly irresponsible. They could have been beyond furious with you (for the sake of argument) and it still wouldn't have been right to subject them to such a display of anger. There are ways and ways of dealing with things and frightening kids with your hissing and shouting - not to mention conveying the impression that they're not wanted - is really pretty horrid.
And that's before you get on to your childhood and what was automatically expected of you. Sure, in an ideal world families should help each other out but sounds to me like you were put upon and expected to take on far more responsibility than a child should have been. Like you, I wouldn't have been best pleased to have been admonished so roundly for 12 hours of unexpected additional care (which was likely caused by illness anyway) when I'd done so much for them in the past. Sounds to me as if your teens/early 20s were dominated by their needs with little or no thought given to you as an individual other than what you could do for them - how useful you could be to them. In fact, you can pull out all the old clichés about two wrongs not making a right and all that but good god, I wonder how much of a 'typical' childhood you missed out on - as opposed to a single 'quiet Sunday' ?? Let's get some perspective here.
Sequins - they sound toxic. Their reaction was NOT normal, and you are NOT the devil incarnate, please ignore all the rubbish you've had here. Thing is - and I apologise if I'm putting words in your mouth - I can imagine that you were already feeling pretty shit when you started this thread .... because it's not just the upset of this particular row is it, but I should imagine that such a judgemental and hypocritical dressing down from your parents would be a very unpleasant reminder of how little you seem to mean to them. You've probably felt that for years and years now - and this has probably also been reinforced by their lack of interest in your children and their unwillingness to help you out (sure, it's true there's no law stipulating grandparents must help out with grandkids, but jeez, when someone's completely on their own, you'd kinda hope it might occur to them to give you a break - graciously - every so often, because they care about you and appreciate it's hard with no support). But, if you're anything like me, you're saddened by the lack of interest and lack of support .... so, when on rare occasions, your parents do show some small kindness it means a lot .... and then, if it all goes tits up it can be quite a severe blow emotionally because you go right back to square one, metaphorically speaking, and yet again, you have to face up to the hard fact that actually, your parents don't really care very much about you at all. Not least because they refuse to recognise that everyone makes the odd mistake and whilst they might be annoyed, it doesn't tally with the 'never darken my doorstep again' type reaction.
So .... you're probably dealing with all sorts of feelings right now, feeling very hurt, having reminders of a pretty crap advantage-taking childhood resurfacing because of what's gone on .... and you come on here, and effectively get burnt at the stake. Ridiculous, and unfair, and no empathy at all from people who can't think outside their own boxes for a moment.
As I said, really hope you still manage to have a good Xmas. It's fantastic that you have a good relationship with your siblings so still have family to celebrate with.