where are my photos on my Mac

Hi - I'm assuming here you are using the photos app, and not iPhoto (the upgrader tool suggests you were upgrading an iPhoto library)

They will still be in your original library.

To open it, hold down the option key. The resulting pane will show you all the libraries on your mac. Your original is most likely called "photos library.photoslibrary". Click it and open. If that is not the one, try any others, using the option key open each time.

It depends if they are shortcuts to the app, or the actual library files. Click on of them and hit CMD-I

What does it tell you about them - especially the size?

Where are the libraries you found with the Option open method?

Look in your pictures folder, do you see any other Photos Libraries?

Sorry, should have said "Hold down the option key while starting photos"

So close photos.

Hold down the option key, and open photos, keeping the option key held down.