everytime i log in to my laptop, my desktop is set to the default, no files are saved, and any changes i make are lost.

hello! my laptop just went through an update, but this problem arised a few days after.

so, whenever i open my laptop, and after i log in, (the password has not changed or anything.) my desktop background is set as the default "blue windows," the taskbar is also on the default settings, i think, all my files are gone, and whenever i make changes to the computer, such as signing in, or changing the taskbar or background are gone after i turn off the computer, then log back in, as if it resets everytime. the first time i logged in and saw this, there was a notification that i was in a temporary account. but, all times after that, that notification does not show, but instead it shows one that informs me that theres a problem with my microsoft account. i can sign in if i click the notification, but, like i said, after i turn off my laptop it signs me out. i've included a photo of my desktop when i first log in. the applications i already had on there before this problem are still there, but, like all of the apps, have been moved to the left side. i'm honestly quite scared that i'm going to lose all my files. i'd be so grateful if someone could help me!