Messed up want to go back in time

Hello unity community, I have really messed up and accidently deleted alot of my stuff I re imported everything now I have it all back but alot of stuff in the scene is gone. Does anyone know how to go back if they mess up.

Undo is always an option.
But usually it is extremely difficult to pristinely rebuild a project after deleting things.
If you want to just have things back in the scene, locate them in the file manager and drag them back into the scene just as you did the first time.