OSX disk space shows 200GB as "other"
You should run DaisyDisk on your mac. It will give you a graphical mapping of all the space on your drive. The app is about $10, but has a free trial you can use. Just download it from the link.

There is also an older version names Disk Inventory X which is Donationware. It says on the link:

Disk Inventory X is a disk usage utility for Mac OS X. It shows the sizes of files and folders in a special graphical way called "treemaps". 

If you've ever wondered where all your disk space has gone, Disk Inventory X will help you to answer this question. 

For a quick start, please read the readme file on the disk image. Or see a 1 minute video about Disk Inventory X from macbreak.com. 

Both apps take several minutes to scan your disk.