First, if you still have access to the hacked account, rename it if you can and change the password for it.
If needed, change the email linked to it as well. Get control of that account back.
As all iTunes purchases are linked to the account that purchased them (music, apps, etc) it is best to rename an account rather than creat a new account. Apple ID's can't be deleted or merged either.
Apple IDs cannot be merged. You should use your preferred Apple ID from now on, but you can still access your purchased items such as music, movies, or software using your other Apple IDs.
If you need further Apple ID help, you will want to contact Apple, Apple ID Support
or maybe iTunes Support