i can think of 2 ways of doing it
1 : al the ot databases are the same, so you can rename everything and everyfile, and reset your phpadmin users in your cpanel
2 : just reset everything and do not allow any1 to access the databases, exept the panel admin, in most of the sites some people create an user just to access the database, if any1 has that user allowed well your gonna be hacked over and over again
so i belive you should export your databases if theres nothing wrong with them, and then take down your website, erase everything in your host, and re-upload and import
you didnt give us any details, like :
the hacker threats me to give him items or some shitt like that (newbs)
the hacker its hacking a seerver dedicated hosted on the u.s (if so tell your host to persuit him from hacking their servers an u.s laws will apply, if he is in the u.s)
the hacker just makes random shitt (now thats weird, thats probably you, making mistakes, or some1 that its making sql injections on your website something like
in rows[][] bla bla items or pacc or something, trought a .php file that he upload to your server, or edited on root, wich i really doubt it)
test all your website files, and refresh your database, to see if theres any bug around, if you open a window and suddenly sql makes an entry, do it 3 times if it happends again its mostlikely a wrong insert intro
with that been said, we dont know anything, and i advice you to not post any data that might put in geopardy your server again.