Help!!! Changes lost!!!

I have a big problem. I was editing a file, which I saved in "acrobat", and changes from October 30 were not saved by the system. The application of "Acobat" I have in my portable device showed that the changes were saved. But suddenly, today, November 28, the application of my portable device had no recent files. When I selected the documents in "Acrobat" asked me for a new password. I did the procedure. When I finally open the file, the changes from October 30 did not exist. They were very very important! Please I need a solution ...

Excuse me about my english.

Greetings.

Martin.