Hey, so a lot of my files just disappeared? (Windows 11)

I was playing on my PC yesterday as usual, I pressed the power button to turn it off as usual and the day afterwards when I got on and a lot of my files were gone? My downloads were untouched, but my windows pictures file was completely empty along with a lot of my apps like Steam and Discord asking me to relog in. It is pretty important to me that I find out how my files just disappeared and how to stop this from repeating in the the future, if you want any further details or got any further questions just ask. (I don't know exactly how to format stuff on reddit since I don't use the site up so any mods tell me if I've done something wrong so I can do redo the post)