All my Microsoft 365 apps are gone from my desktop and start menu after I reboot my laptop.

I reboot my laptop and as soon as it opened, I noticed that all my Microsoft 365 applications are gone from my desktop and start menu. Not just the Microsoft 365 apps but my other applications as well (anti-virus, IDE, etc...) Whenever I search something in the search bar it says, "No apps matched your search". I checked my programs and features, the applications that I am looking for are still installed. What should I do? I am running a Windows 8.1 by the way.