If you were truly hacked, I would work on finding out how they got in and what method(s) they used. Changing your password really won't do any good if something has been installed to monitor changes to the system, passwords and so forth. If that is the case, the hacker will be able to easily retrieve the new password, login again and continue onward.
If you're not able to resolve how and the method(s) used, it'd be best to contact your web hosting provider and see if they can offer some aid.
