If you have just lost your change sin Evernote, you can recover your note using local files backed (should be up automatically - if not be sure to switch it on!)
Mac
1. Go to Go, hold down option key, select Library
2. Search for Evernote in the Library folder
3. Sort the version history by "last modified"
4. Double click the first or second note in this list
5. Give your note a new name and move it to the relevant folder.