Re: Photo deletion (100GB) did not free up storage
Thank you for your post to the community, and for sharing what you have tried already.
If you haven't already: You could try restarting Mac (Apple menu . Restart).
Then check if the storage amount has updated.
Else: Wondering which MacBook Pro model (year) and MacOS version / photo app / you use.
Could there be a "Recently Deleted" album where the photos may be recoverable for up to 30 days, before they would be permanently deleted. If so, you could try to permanently delete those photos.
or
If photos are synced to iCloud ... likely can't have them there without being on Mac as well.
Eg: Try storing them on a external storage drive