photolibrary appears to be corrupt

What Old Toad said, and

Where is your Photos Library located? Is it on an external drive? If so, how is this external drive formatted? To avoid damaging the Photos Library an external drive must be formatted in either APFS format or Mac OS Extended (Journaled) format. Additionally, the drive can not have had Time Machine on it since it was formatted. There have been so many problems with using incompatible drives that the newest macOSs won't even allow a Library on a non-Mac formatted drive to open, since there is a chance of damaging the Photos database. See this:

Move your Photos library to save space on your Mac - Apple Support

Please read the following user tip and restate your question/problem in detail: 

     Writing an Effective Apple Support Communities Question - Apple Community

What year and system is your MBP?

What happens when you try to open the library?

Are you able to launch Photos with the Option key held to get the Select Library window?

Have you tried opening the library with the Option+Command keys held down to rebuild/repair the library?