Soooo I think I was hacked... What do I do?

I was on a website and someone told me they were a website moderator and that they would close my account if I didn't put "semi-nude" pictures up and told me to contact the administrator on skype... which I thought was extremely weird. So I looked up the name and he told me he would hack my stuff and put on a "net ban" if I didn't put up pictures that I didn't want to put up and would have all my accounts linked to my email deleted. he told me if I didn't skype him he would leak my personal info so I blocked him. Then 15 mins later I got a request from a person of a name I knew so I accepted and he told me that I oped all my personal info and he would send all of the things i had on my computer to everyone I know..... He went on my email and I know he changed some stuff so I immediately deleted all my accounts and created a new email and changed my fb email.... I'm so scared how can someone do this? what should I do? :/ im only 15 years old