80+ GB of other in storage - nothing's working to help clear

So. More than 60% of my laptop's HD storage is being taken up by 'other'. And at this point I'm at a loss for fixes.

In terms of files, applications, and messages, I'm only using about 20GB of the HD's 121GB. System's taking up about 12GB. The rest is totally full of 'other.' At this point, it's running at about 700~MB available. Went to Disk Utility > Macintosh HD : 11.36 GB Used, 109 GB Other Volumes, 700~ MB Available. Disk Utility > Macintosh HD - Data : 106 GB Used, 14 GB Other Volumes, 700~ MB Available.

I've gone through and manually deleted caches, I've ran a disk cleanup software, I ran maintenance scripts. Barely made any kind of dent. I got recommended OmniDiskSweeper, and after doing a scan and sizing, it's only picking up 70 GB to review off the HD, and there's nothing really raising any red flags.

HELP LOL