All my photos gone from my photo app in my macbook pro mid 2012

So basically I wanted to change my wallpaper and saw that I had a photo library that I didn't know about and not connected to my actual photo library in my computer, so I went to check through finder and clicked on users, my user, pictures and clicked on the logo of the Photo application. Then it opened the app and displayed those pictures I didn't know about, however all of my previous imported photos (Around 10 thousand) didn't appear which I found strange.

After I was done looking I wanted to go back to normal and see my old Photos app with all of my pictures and imported pictures in it, but I couldn't. I also moved the fotos with the app logo into my desktop so I could see how to organize it later.

Its been around 2 hours and it seems as if all of my photos are gone, I tried opening them again from the finder following the same steps as before but there was another shortcut but with a different name but same logo of the app and when I clicked it it opened yet again the photos app but it said that there were no photos and that the only ones where the mystery ones.

I downloaded vlc to search for them but it says that what I think are my actual photos can't be opened.

I don't know what to do and I'm so so scared that they might be gone forever as I didn't have a backup for them and only stored them in my computer on the Photos app.

The device im currently using is a MacBook Pro mid 2012 using macOS Catalina 10.15.7 that was bought second hand many years ago.

I also don't have backups for my computer data or even know how to use Time Machine. The computer is used just to store things and work purposes.