This is very scary, indeed. I'm terribly sorry this happened to ye', Rita. Like DelightfulRevenge said, perhaps it'd help if ye' were to create a new account and leave that hacker to his own devices. I don't think changing your password would help, as ye've already stated that it would not work. Hh- I do hope this issue goes away. There are some nasty people out there, I swear.
I also hope your friends will understand the situation. It's rather awful what the hacker did to ye' and I'm truthfully very sorry.