Illustrator could partially read this file

All of a sudden any file I have created in the last year that is over 70mb is unable to be opened. I get the error message illustrator could partially read this file - then when I open it is  a blank page or only has a little bit of copy left in it.

I have a BRAND NEW macbook 2023 M2. I recently reinstalled illlustrator and am working in 28.1. My operating system is Sonoma. I save on the computer and it is being backed up both by google drive and my external hard drive.  I have plenty of memory. 32G 

This is totally unacceptable .I work from home and do not have an IT department so I need to find a way to open my files which were accessable a day ago.  I can see the preview image in the last files open and it has all the information in the thumbnail visible . But the files are not readable when I open them aka - they have NOTHING in them.  

I have sent an email with links to the files to the files@adobe address - but from what I see in this forum there are serious issues with recovery. 

I pay way to much every year to adobe to now not be able to recover all my work please tell me all is not lost.