GMail - All Messages Lost - Not Showing in Trash etc.

john1

This may help 

Restore messages from the Admin console

After 30 days, admins have 25 more days to restore deleted messages from the Admin console. Follow the steps below, in Restore Gmail data from the Admin console.

After these additional 25 days, messages are permanently deleted from the Admin console, and admins can't restore them.

k_man

john1 said:

This may help 

Restore messages from the Admin console

After 30 days, admins have 25 more days to restore deleted messages from the Admin console. Follow the steps below, in Restore Gmail data from the Admin console.

After these additional 25 days, messages are permanently deleted from the Admin console, and admins can't restore them.

Unfortunately that relates to business/Workspace accounts, rather than personal GMail ones.

However Google support may have access to something similar

debitcardmayhem

not sure if this helps https://support.google.com/mail/thread/7668250/how-do-i-retrieve-archived-emails?hl=en