So I tried downloading Cyberpunk through my library on the GOG browser but it didn't work, it simply says an error occured. I tried to download GOG Galaxy and it says the exact same thing. Troublesome. Can someone help?

Sounds like a gateway/proxy/DNS issue.

If you're using a VPN, try changing locations, try resetting your internet connection/router, and maybe reset the computer and try again. Might also clean the cache in your browser.

If problem persists, well we'll figure something out.

What changed between now and last year?
Do you have a new system?
If not - did you de-install the game properly from your system?
Or do you still have access to your old install (probably the best case scenario)?