I have all of my photos on my Mac but the albums I created have disappeared, also half the photos I marked favourite have no longer been marked - help?

Can you please provide more background information? What has changed before it no longer worked? What happened directly before the albums disappeared?

Did you install a system update? Did you enable iCloud Photos? Did you move your Photos Library to a different volume?

Sometimes it looks like albums or photos have vanished, because you accidentally opened an older version of your Photos Library.

• Quit Photos, if it is running.
• Hold down the options key ⌥ while launching Photos again. When the Library chooser dialog appears, release the options key ⌥ and select your main Photos Library.

Are you now seeing your albums again? If not try all libraries in turn from the Library chooser dialog.

Great😊 You're welcome.