HOW TO REVERT TO PREVIOUSLY SAVED COMMENTS ON AN ADOBE FILE

I'm on Mac.

I had a PDF file with content in French I needed to translate into English for a client.

I added my English translation content into COMMENTS as instructed all over the original French document.

I saved that version as "English version" in FDF format (PDF would have been fine but my mac automatically created an FDF format).

I also needed this file with the comments not in English, but in Spanish too. So I duplicated the file, renamed that duplicated file "Spanish version", and replaced the English comments with Spanish content. I saved that version again.

So I now have two files : one English version, one Spanish version. All good.

However, when I open the English version, ALL COMMENTS ARE IN SPANISH just like in the duplicated version: it's as if the duplicated Spanish version has overwritten the original English version. I now have TWO IDENTICAL SPANISH VERSIONS despite different file names, and I have LOST ALL MY HARD WORK of the English version...

How can I recover the file's previously saved versions ? On Mac, there is no "recover" or "browse versions" feature when clicking right...

Furthermore, even when I click "REVERT" to original format when the FDF file is open, the comments are STILL IN SPANISH.

I'm very worried.

Any help ?

Thanks a lot