All the scripts in my project have been corrupted, and entire Hierarchy deleted

I have made an almost complete project on maze pathfinding algorithms, but now when I launched my project today, my entire game hierarchy was deleted! I do not mind this as I'm sure I can remake all the GameObjects, however tedious it may be. But my scripts had a few hundreds lines of code each.

I get this error five times 'Unknown error occurred while loading 'E:/AI Project OLD/Assets/Scenes/maze.unity'.

As well as 'Assets/Scripts/MapData.cs(1,0): error CS1525: Unexpected symbol `PreviewAssetData''

This is for my university coursework so help would be much appreciated. My last backup was foolishly made a week ago where my progress is a large amount of hours from where I was at before the corruption.

But all my scripts are not displaying the code and instead have all been changed to either this:

Code (CSharp):

 PreviewAssetData    BaseName:
   mainRepresentation:
     serializedVersion: 3
     name: Settings
     thumbnail:
       m_Format: 0
       m_Width: 0
       m_Height: 0
       m_RowBytes: 0
       image data: 0
       _typelessdata:
     guid: f23a31d05c4426148aafdcd13bf8ef04
     path: Assets/Scripts/Settings.cs
     localIdentifier: 11500000
     thumbnailClassID: 115
     flags: 0
     scriptClassName: Settings
   representations: []
   labels:
     m_Labels: []
   assetImporterClassID: 1035
   assetBundleFullName:
     m_AssetBundleName:
     m_AssetBundleVariant:
   externalReferencesForValidation: []
 AssetInfo_______?  

Or this: (sorry from the long text) Code (CSharp):

   %YAML 1.1 %TAG !u! tag:unity3d.com,2011:
 --- !u!47 &1 QualitySettings:   m_ObjectHideFlags: 0   serializedVersion: 5   m_CurrentQuality: 4   m_QualitySettings:
   - serializedVersion: 2
     name: Very Low
     pixelLightCount: 0
     shadows: 0
     shadowResolution: 0
     shadowProjection: 1
     shadowCascades: 1
     shadowDistance: 15
     shadowNearPlaneOffset: 3
     shadowCascade2Split: 0.33333334
     shadowCascade4Split: {x: 0.06666667, y: 0.2, z: 0.46666667}
     shadowmaskMode: 0
     blendWeights: 1
     textureQuality: 1
     anisotropicTextures: 0
     antiAliasing: 0
     softParticles: 0  {}

(I have cropped the second code - the full version is in the file attached)

I have tried using Recuva to maybe fix the files and get the code attached to them but it just displays what I wrote above instead of the actual code. This is on Unity Version: 2018.4.12f1 How do I fix this? Thank you