Sorry to hear what happened. Try the following and let me know if this works:
Open the document you saved over, then choose File > Revert To > Browse All Versions.
Click tick marks along the timeline to browse versions.
Display the version you want, then do one of the following:
To restore your document to this version, click Restore.
To duplicate this version in a new document, press the Option key and click “Restore a Copy.”
To delete this version, move the pointer to the top of the screen to show the menu bar, then choose File > Revert To > Delete This Version.
If that does not work for you or you do not see the options I explained above let me know.
You may not have had auto recover enabled. Try the following though just to check:
Open the Word file that you saved and now want to restore to its previous condition.
Click on the "File" tab and and select "Info."
Select the version you want to open in the Versions list. Click the "Restore" button when the file opens.
Yes you very well could be I am sorry to say. Newer versions of word make this easier and of course time machine is ideal. But when you save a file over a file it totally replaces it.
Usually what I tell people in this situation is to make a judgment call, which would be, would it take more time to just do the work again OR would it take more time to keep trying recovery option that may or may not work. Usually in most cases if you do not have a back up or the option in word to restore to an earlier version than you are out of luck. It really depends on the document but most of the time in this situation it is more efficient to just do the work again and take the lesson learned.
I know it is frustrating but honestly without having the options available I mentioned above there is nothing more that can be done I am sorry to say.
One other thing I should mention, if you did not close the document and made changes and then saved you can try to undo the changes by using the command Z. This will only work though if the it is the same files and you did not close it.
If it was a new document and when you saved it you overwrote another document then I stand by what I said above but just thought I should mention that as well just in case.
At this time please take a moment to rate me by clicking the stars above, 3 or more please to acknowledge that I have had this conversation with you and while you may not like the outcome you did receive a professional consultation.