Stalker still stalking?

[Kassy]

So I do have a Facebook, and I got a message like 8 months ago from a random stranger. I was like whatever I'm gonna ignore you. But, I dated this guy who knew my password, he talked to the stranger telling him I loved him and all this stuff.. I found out he's a 30 year old from Australia. I live in the USA. So.. There was a storm here and I couldn't go on the Internet for about 2 weeks. Through out that time, the bf (who's now a ex) was telling him (the stranger) personal things about me, causing our 'bond' to get larger. So I finally get on Facebook and see the messages. I tell the stranger who we'll call David that it wasn't me talking to him. He didn't believe it so I was like okay whatever idk you. So I blocked him. He made a new account and started messaging me there. It was creepy so I reported him for bullying since he was calling me a slut and crap. And I blocked him. Over the months, he kept making new accounts to bother me! HE TOLD MY PERSONAL SECRETS ON HIS FACEBOOK! Ugh. So I reported the post and blocked that account. I told my parents about what's happening, they told the guy and he stopped stalking me. BUT! 2 months later, GUESS WHO'S BACK! Yeah, him. So I blocked that acount, and made myself a new acount so he couldn't bother me. Well guess who found me! Anyways he's just been bothering me A LOT! I've tried so many things to make him quit it but honestly he's not leaving. I ignore him but he threatens to post pictures of me 'naked' that the ex sent. He photoshopped my face on this random naked girls body. (Messed up!) so any advice on making him leave? (Not using Facebook is not an option. I help troubled teens/adults.)