Hacked, can't get config right
 

We were hacked, with the site inoperable. My host insisted I changed all domain logins. This has changed the database name. The password I have on file is not recognized as the old password, which I need in order to create a new one. I tried creating a new user and password, and entered those in the config file, but it still doesn't work. How can I troubleshoot this?

Thanks