Without a backup, I think you are out of luck. There is a way to manually merge sd cards (I've done it before), but it's a bit of a pain to do. Here's an example on how it works, for future reference.
I'm just assuming that no sysnand hacks interfere with this method.
It's not the movies or games downloads that I would worry about, like breaking into networks, downloading encrypted things, spying on network traffic. I have seen so many "Top Secret" seals on files when I was a kid
I was obsessed with finding UFOs, a surprising amount of US files where stashed on computers in other countries, China back in the early 90s omg sooo much