I need to vent cause I'm freaking out

So for like, a couple weeks I guess, I've been just a little obsessively worried that my 54 yo mom is getting dementia. It just popped up out of nowhere. She's still running the house like normal, and does dishes normally and even cleaned my room last week, but after a misunderstanding on my part a few weeks ago when I thought she forgot something but didn't (I just heard it wrong), and it just started a spiral from there.

I was getting better until like yesterday when I read this c.ai bot where the character got dementia and it went into detail and everything. Now it's at the forefront of my mind. Yesterday I was super worried, since she even seemed to occasionally pause to come up with a word, like salivate is an example.

Then today, I was fine around the afternoon today, or at least better. Then I went swimming with her and I don't know, she was normal and everything and made the joke I was expecting her to when I was expecting her to but just like, a couple seconds after I thought she would. But for whatever reason it made me all worried again.

There's my nearing-tears rant, so good day. Or if anyone wanted to advise me on whether or not I should be worried that'd be great since I kinda go 0-60 worry a lot.