Photoshop CS5 download, key no longer working

So, I recently got a new computer(Hi, stimulus check!). Given computers no longer have CD drives if you don't build it yourself, I've been relying on downloading CS5, which I got way back in 2013, since I've also lost my CD for it in moving cross-country. Well, I last installed it on my previous computer some... 4+ years ago? And apparently...

Things have changed.

I can't find a download anywhere on the Adobe website, because everything is insistently /Creative Cloud/, which is a SUBSCRIPTION. And I'm a broke retail worker who's not keen on paying a subscription for a program I've already bought, thus shelling out way more for it in the long run than I can pay one-time, just to USE it, and I don't use Adobe Photoshop for a whole grand lot, mostly just coloring stuff.

Can you figure out where this is going?

Yeah, I had to find somewhere else to download it, which I would very much rather NOT have to do.

(You know, Adobe, y'all could make a LOT of money if you let people buy older programs, even at a discount - Just have the stipulation that other than getting it to WORK when you install it, you're not really supporting or updating it. That'd be very lucrative!)

And now, my key that I've used for nearly 7 years... Is not working. Without having to pay a subscription fee I literally CANNOT afford, is there ANY way I can fix this? Again, I don't use it for a whole lot, and I'm not into subscriptions for using products I've bought, and CS5 is the version I'm used to.

For reference, I'm on Windows 10 right now.