My finder libary, System Preferences is missing on my mac after updated to Catalina

Hey everyone, I recently updated my Mac from El Capitan to Catalina and now I can't open my Finder, Itunes, App store or System Preferences. Does anyone know what I can do?

When I try to launch my System Preferences it says " System Preferences quit unexpectedly"

When I try to launch my finder it says "The application “Finder” can’t be opened." and "Finder quit unexpectedly".

Everything is running slow, even typing this message there is lag.

Please help me

Thank you