It looks like you are saving files into your email app. The email app might delete temporary files (your edited files) from time to time when it cleans or compacts.
There is one place that Microsoft sets up for documents; it is call Documents and is at C:\Users\Connie\Documents. You should save email attachments that you want to edit or store in that place, preferably in suitable sub-folders, and edit them from there.
This page might be helpful, File management - The Document Foundation Wiki
BTW always save in .odt format, you will lose functionality especially with rtf. If you need to share with someone else who cannot afford LibreOffice then you can Save a Copy in another format for them; don’t continue editing the foreign format copy