I'm in a grt problem?/ someone has hacked my password... is there any way to get back the hacked password?

Follow the forgotten password links and go from there.

Yea ih done that but the hacker has changed my password n changed the security question also...

Depending on what the account concerns, you may be able to just create a completely new identity and login.

In your case, your only option is to contact the service directly and attempt to prove its your account.

You should also contact the people or organisations that send you mails...