The app being damaged does not mean the message folders are damaged. If you haven't yet deleted anything, I suggest you locate and copy the entire profile to a safe place so you can install fresh and then reconnect the profile.

thanks for this response and sorry for the delay in responding - the problem was that the app was completely frozen so i couldnt even access the profile in order to save it - my only option was to delete the app and, so i thought, retrieve a copy from out of time machine - no matter how far i went back i still got the message 'the app is damaged please move it to the trash'

The profile should still be there. Check in c:\users\<yourid>\appdata\roaming\thunderbird\profiles if the profile is there, you can download a fresh copy of thunderbird and install it.

after <yourid> i couldnt find 'appdata' and everything after it - what i did find are what i show in these two screenshots - altho i am wary about the mention of googlemail in one of them - ie this could be the profile attached to my gmail account ?

ps - all the detailed entries seem to date back to july 2014

This doesn't look like Windows? A Mac, maybe? Anyway, you show two profiles, but I noticed abook.mab, which was the addressbook prior to the newer abook.sqlite. I think that switch happened with version 78 (but that's a guess). So, although these are profiles, I agree that they are too old to be your profiles (unless you were using an old version of Thunderbird). Look at the dates for the message folders (e.g. inbox) as that will be a clue. If any of the dates are recent, then you've found your profiles. The profiles.ini file is a text file and if you open it, it will tell you which of those two profiles was the active one.

could this be the one ? if so how do i save it and import it ?

I would have no idea if that is the desired profile, but it is a profile. Your system doesn't look like windows, so I'll try these steps.

click tools>import>import from a thunderbird profile and then click 'choose a profile folder'

Download and install from https://www.thunderbird.net/en-US/download/

If your data does not appear, then do Help > Troubleshooting Information > about:profiles

You should see a list of profile names such as Profile: default Profile: default-release etc

Your data will be in a profile that a) is not marked as "This is the profile in use and it cannot be deleted." and b) is most likely default-release

Click "Set as default profile". Exit Thunderbird. Start Thunderbird.