Contact the Facebook management Team to retrieve your
account.
Create a new email with unique password different from the one
you use normally.
Include upper case letters , numbers and symbols.
Change your existing Email to new Email , change password
frequently. (eg.every week)
Turn on secure browsing (https)
Uninstall , avoid suspicious apps on your Facebook.
** IMPORTANT **
Turn on SMS notifications so you will know immediately if
someone logs in to your Facebook account.
Turn on notifications when someone logs in from a different
location.