Hello agould520,
Thank you for reaching out to Apple Support Communities, and we'll be happy to help in any way we can. We understand you're having issues with opening the Photos library on your Mac. Try the steps here to see if they resolve the issue: How to use the Photos Repair Library tool on your Mac - Apple Support
"If your Photos library won't open or if the Photos app behaves unexpectedly on your Mac, the Photos Repair Library tool might help.
Before you use the Photos Repair Library tool, back up your photo library. You can use Time Machine, use a third-party backup solution, or copy the library to an external drive. By default, your photo library is stored in the Pictures folder within your home folder.
To get to the Photos Repair Library tool on your Mac, follow these steps:
- If Photos is open, close the app. Then, while you click to open Photos, hold down the Command and Option keys at the same time.
- In the window that opens, click Repair to start the repair process. You might be asked to enter your user account password.
The Repair Library tool analyzes the library's database and repairs any inconsistencies it detects. Depending on the size of your library, the repairs might take some time. When the process is done, Photos opens the library.
If you repair a library that's used with iCloud Photos, iCloud checks the library after the repair process completes to ensure everything is synced correctly.
If these steps don't work or you can't open the repair tool, contact Apple Support."
We hope this helps.
Cheers!