So this one isn't in-game but it's regarding files. I downloaded a mod with Forge and I put the mod in and when I put the mod in my file folder, I obviously exit the file explorer and I go to play the game and my worlds, installations, skins are all gone. I know this is a save file I downloaded because 12,000,000 people downloaded it and had no problems and it's on a trusted website I download mods from all the time. After my world were gone I go into my .minecraft folder again and it's nowhere to be found anywhere on my %appdata% folder. I restart my PC and it's there but without many of the files it needs. Can you please fix this if you can and please tell me a way to recover my files.

I had 50 worlds in the saves before