@Ellyfinsmum I absolutely believe you. I'm a huge skeptic, and to the best of my knowledge I haven't experienced anything like what you described. Two things spring to mind:
Recently I've been a bit hooked on a website called Ranker. It's a series of photos with a short description for each, on lots of different topics, and you can rate that pic (no account needed). For example, just yesterday I found myself on a Ranker page about so-called 'time travellers' whereby photos, mainly from the past, apparently showed something very unusual in that somebody captured within that photo appeared very out of place. For example, a photo taken in the 1940s appeared to show a man in a crowd and he was using what looked like a smart phone. You can 'vote' whether you find that photo interesting, creepy etc. Of course, photos can be edited using highly sophisticated technology to make the look genuine even when they're not, however people's experiences - like yours - cannot be edited like that (that we know of). That leads me onto my second point...
A few weeks ago I was browsing MN and reading a thread similar to this. One person described how she'd been travelling with a companion on a very familiar route by car and both of them saw an old/ancient stone bridge covered in moss. Neither of them recognised the bridge and had never noticed it before. When travelling on that same stretch of road a short time later, the bridge wasn't there.
As a PP said, humans are very ignorant to assume we know all there is to know. Clearly we don't, and whatever the true explanations, there's good reason we don't know.
Your experience sounds utterly terrifying and bewildering. I've had a few very strange experiences which I can't explain but nothing on the level you've described here.