LOST: A book I was working on for a YEAR!

I've never used their file recovery service myself, but Markzware offers a paid service that can often recover material from damaged InDesign files.  

This might be helpful (for future documents):
https://creativepro.com/backups-for-busy-creatives/?utm_source=CreativePro+Network+List&utm_campaign=969bb9dafd-cproweekly_02-21-2024&utm_medium=email&utm_term=0_98b7b678b4-969bb9dafd-260745842&mc_cid=969bb9dafd&mc_eid=1e3731c216

While I sympathize with your plight, I cannot imagine working on something so important without proper backup. Were you by any chance working in a Dropbox or OneDrive (or similar) folder? What version of InDesign? What operating system?

It seems the horse has bolted but please tell us you've got daily backups.

Your screenshot shows you're on a Mac. Time Machine is built for these situations. Just connect an external hard drive to your Mac.

Back up your files with Time Machine on Mac – Apple Support (AU)

Do any of these suggestions help?

Recover documents and undo mistakes in InDesign (adobe.com)

Is a lock file aside the indd file? Delete it?

Did you package the file with an IDML included? Work on with the idml. 
Did you make copies in case of problems? You should always do that. 
Did you work on a cloud drive like Dropbox? The have tools to recover any file for a period of time. 

when you worked did you link or embed used images and other assets?

If nothing helps you need to start and make security steps in the future but your files are lost.