Stop sending money to strangers, if you can post the details of the facebook account that convinced you and scammed the money and the accounts in which you sent the money, people here might help you in finding the person behind the scam .
The best thing you can do is to register a case and i presume it is an international fraud case and i am not sure how the authorities will be dealing with it and since you lost a fairly large amount of money the authorities might help you in identifying the IP address and other details but the possibility of getting it returned is really slim.