Unsettled by Trend implications, quite upset - anyone else get unsettled by this?

So last night I had an hour’s conversation on the phone with my lovely sister. She’s great in so many ways and has helped me out a ton in recent times. 
 
But there’s this thing that comes up now and again since my diagnosis. It’s not about me, at least not overtly or consciously. Despite initially saying ‘no, you? Rubbish’ when I initially told her about my diagnosis, she did ring me back later that day to say the she’d meant well and shouldn’t have tried to take that identity away from me. And since then she’s never repeated any statement like that first one, instead agreeing that it explains a few things, etc. and like I say, she’s great. Just wants the best for everyone, generous to a fault, all that. 
 
And yet,… even though she’ll add an ‘and I don’t mean you’ she will occasionally bring up this thing of how people now - especially Gen Z or whatever they’re called - are so attuned to all these neurodiversity labels that they won’t hesitate to grab one for themselves, not in most cases (as she is at pains to make clear) inauthentically, but her implication is almost something like saying that the majority of society turns out to be autistic, not the minority. She referenced a meme she’s seen the other day. It was a picture of a queue of many thousands of people at some event, going on for miles. And underneath it said ‘Me, waiting for the launch of Autism’. At first I didn’t understand but she explained that it was saying ‘this is the new trendy thing to have, like the next iPhone, I’m getting me one and then I can be special too… just like every other person I know.’ That kind of sentiment. And when she said this I started feeling really sick and upset and embarrassed. I said, ‘I actually find that [not her, the joke itself] offensive. Do you think I paid a thousand pounds I couldn’t afford after a lot of deliberation and exploratory talks with a GP, after several breakdowns since turning forty and many struggles over the years, because I wanted to be on trend?’ She did make it clear that ‘oh I don’t mean you’ but I did feel very inadvertently devalued in that moment, my identity slightly trivialised. Even though I know she wouldn’t have consciously ever wanted to convey that and I don’t even think that’s how she secretly thinks. She’s pretty accepting for the most part and can see how I fit the bill and why I needed to know and get external confirmation from experts that I’m autistic. And yet it still left me feeling shaken, and I fixated on it a lot afterwards and again since waking up today.

I also said to her ‘look, I know it’s way underdiagnosed. Chris Packham said the numbers are half a million UK, but I’m sure it’s way more.’ I said I’d multiplied by a factor of six to about 3-4% for what was a truer societal picture. She said ‘no it can’t be, it must be waaay more, look - every other person I know at work or online calls themselves adhd or autistic or whatever now. It’s most people really.’ And I was left feeling really confused. Can somebody help me with perspective here? Am I/are we (here) the 1 in 30-ish or not? If not, then what the heck is this support community for the allegedly commonplace all about? Sorry, this has unbalanced me way more than my well- meaning sister would ever have realised, but I feel pretty embarrassed and a bit sick with worry over it all now. Have I been making way too much out of something that’s ten a penny? Have people I know at work who I’ve told been rolling their eyes when I leave the room going ‘god, another one getting on the bandwagon?’ Am i the under-achiever I used to think I was after all, and merely using a label to make myself feel better? No! And yet it must look that way -excuse making- to the gazillion (allegedly) fellow autistics in high power jobs and doing all the conventional things with ease! They are living examples of ‘don’t use it as an excuse mate, we didn’t’ and until last night I didn’t even know that so very many existed. If they do! Do they? Typing this makes me rallies I’m more upset even than I realised. I feel like there’s not just imposter syndrome in the mix but a sort of ‘but can’t you see that I’m one of the REAL ones?’ As though I were in an autistic line up comprising most of society. God,I hate getting into these spirals I need to know that how I’m wired is not commonplace, that the majority are still by far and away the majority. And yet I keep being informed that everyone my family knows and half the people my friends know are neurodiverse or autistic. (Though maybe like attracts like and propagates it too - so there must also be NT people who barely encounter the neurodiverse as they attract their kind to them? Maybe oversimplifying) And that joke/meme thing really hurt. The joke itself, not my sister’s imperfect navigation of it. 
 
Im very unsettled and confused. Someone please help me out of this spiral. Thanks!