Missing disk space after failed bootcamp partition

So a bootcamp installation failed and now I'm out 400gb of space on my drive. I have looked and found solutions but unfortunately I don't have the sufficient know-how to apply them to my situations.

I checked the drive with "First aid" in Disk utility and everything came back with no errors.

iMac (Retina 5K, 27-inch, Late 2015)
10.13.6 High Sierra

/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *121.3 GB   disk0
   1:                        EFI EFI                     209.7 MB   disk0s1
   2:          Apple_CoreStorage Macintosh HD            121.0 GB   disk0s2
   3:                 Apple_Boot Boot OS X               134.2 MB   disk0s3

/dev/disk1 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *2.0 TB     disk1
   1:                        EFI EFI                     209.7 MB   disk1s1
   2:          Apple_CoreStorage Macintosh HD            2.0 TB     disk1s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk1s3

/dev/disk2 (internal, virtual):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:                  Apple_HFS Macintosh HD           +1.7 TB     disk2
                                 Logical Volume on disk0s2, disk1s2
                                 FE896926-6556-4167-9727-6AE772587267
                                 Unencrypted Fusion Drive

CoreStorage logical volume groups (1 found)
|
+-- Logical Volume Group 5B113CF5-AF4E-437D-86BA-94CC9773F3C8
    =========================================================
    Name:         Macintosh HD
    Status:       Online
    Size:         2120528027648 B (2.1 TB)
    Free Space:   458921852928 B (458.9 GB)
    |
    +-< Physical Volume 5C572DA8-7561-4DF2-8CC2-F6BB9092B444
    |   ----------------------------------------------------
    |   Index:    0
    |   Disk:     disk0s2
    |   Status:   Online
    |   Size:     120988852224 B (121.0 GB)
    |
    +-< Physical Volume B439E586-F1C5-4163-84B1-F8C7A95543CF
    |   ----------------------------------------------------
    |   Index:    1
    |   Disk:     disk1s2
    |   Status:   Online
    |   Size:     1999539175424 B (2.0 TB)
    |
    +-> Logical Volume Family 5F980324-88C8-402D-849C-F43C14D00DD8
        ----------------------------------------------------------
        Encryption Type:         None
        |
        +-> Logical Volume FE896926-6556-4167-9727-6AE772587267
            ---------------------------------------------------
            Disk:                  disk2
            Status:                Online
            Size (Total):          1654999875584 B (1.7 TB)
            Revertible:            No
            LV Name:               Macintosh HD
            Volume Name:           Macintosh HD
            Content Hint:          Apple_HFS
            LVG Type:              Fusion, Sparse

Any help would be greatly appreciated, thank-you