That is, indeed, scary. I know because it has happened to me, too, maybe two or three times over the past ten years. Mine come like a menopausal hot flash with a dizzy/nauseous component, but pass within a minute or so and I feel okay again. It's happened so rarely and never was as serious as yours (i.e., making me faint or have to crawl), so I've never pursued it. The human body is a strange thing. Hope you don't have any more episodes! 💜
Thanks Ms @thekittygirl