Mac OS Monterey Lost almost all information in my apple mail sub folders

Thanks for your reply but this did not work plus I may have mislead you as this happened before the upgrade to Monterey

plus all the sub folders over 30 or more are showing up, but all the information that was saved in each sub folder has been lost.

help and advice please

Sandra

macOS 10.15.3 Update:

  Source: Apple

  Install Date: 10/2/20, 11:25

macOS 11.1:

  Version: 11,1

  Source: Apple

  Install Date: 28/12/20, 13:29

macOS 11.2.1:

  Version: 11.2.1

  Source: Apple

  Install Date: 22/2/21, 14:52

macOS 11.3:

  Version: 11,3

  Source: Apple

  Install Date: 29/4/21, 00:20

macOS 11.3.1:

  Version: 11.3.1

  Source: Apple

  Install Date: 24/5/21, 09:09

macOS 11.4:

  Version: 11,4

  Source: Apple

  Install Date: 21/6/21, 15:42

macOS 11.5.1:

  Version: 11.5.1

  Source: Apple

  Install Date: 8/8/21, 14:08

macOS 11.6:

  Version: 11,6

  Source: Apple

  Install Date: 17/10/21, 20:50

macOS 12.2:

  Version: 12,2

  Source: Apple

  Install Date: 25/2/22, 15:59

macOS 12.2.1:

  Version: 12.2.1

  Source: Apple

  Install Date: 25/2/22, 17:37

macOS Big Sur:

  Version: 11,1

  Source: Apple

  Install Date: 28/12/20, 12:49

macOS Catalina 10.15.4 Update:

  Source: Apple

  Install Date: 24/4/20, 21:55

macOS Catalina 10.15.5 Update:

  Source: Apple

  Install Date: 8/6/20, 12:55

macOS Catalina 10.15.6 Update:

  Source: Apple

  Install Date: 25/8/20, 12:30

macOS Catalina 10.15.7 Update:

  Source: Apple

  Install Date: 2/11/20, 00:40

macOS Installer Notification:

  Version: 2,0

  Source: Apple

  Install Date: 15/1/22, 16:52

macOS Monterey:

  Version: 12,2

  Source: Apple

  Install Date: 9/2/22, 13:58

macOS Monterey:

  Version: 12.2.1

  Source: Apple

  Install Date: 25/2/22, 12:24

Thank you for your response, its not a great deal of help to you but to be honest I can not pin point the point of time of the loss, as I have not had the time to be able to pursue the issue. also I was trying to dump Google drive as I have apple iCloud and felt there was not a need to have both

plus the cost factor. plus I have a old time capsule which upon trying to go back to where the folders once where. I have not had any luck. plus being a much older person the mind goes a bit brain dead. at times.

but I am grateful for any suggestions

Sorry I can not remember what the name was before the this up grade other than it would have been the previous up grade

Ha Ha that made me laugh but have you got any other suggestions or am I on a loser !!!

Thank you for your reply for which I understand the situation Sandra