There is such a thing as toxic positivity, OP. People are allowed to have bad days, or even just be fed up.
It sounds like total overstimulation and tbf to your sister, I get this a lot. I loathe strangers bumping into me, try to avoid it, and when they still manage to when I've moved out of the way to avoid them touching me, get the range. I don't like physical contact with strangers and would prefer they don't touch me, particularly when there's not a need to.
Dog owner too and loathe badly behaved dogs. There's no reason they should be jumping up on strangers, it's unpleasant.
The repetitive banging of the windows would also get to me. It's jarring and I find it overstimulating.
Finally ,there's nothing worse than having a day full of noise, unwanted contact with other folk, then getting home to your safe space and you can't relax because your neighbours are noisy dicks who insist on shouting when outdoors.
I might not utter 'someone is out there to get me' as if I'm sort of victim, just more recognise the fact I'm grumpy, don't deal with this stuff well due to my anxiety, and it's been shit. But I totally feel your sister on this one.
It's also super annoying to listen to people moan constantly, so if it bothers you tell her to tone down the moaning a bit cos it's doing your head in and unpleasant to be around.