My epic fail erased the main level

While adding new bits and pieces to the scene I thought it become hard to find the assets maybe it would be better to separate them as materials, animations, etc. like we normally do but me 'the Megamind copied and pasted all the asset from file explorer not from the editor so all the prefabs go missing in the main level  -also the only level- all my level editing work blow up actually I wanted to change that a bit so this accident helped me a little but I am not sure the game will be ready when time out.

Here is the new entrance you probably noticed the farm fields are out of the wall now which is more accurate.