How can I recover my hacked Apple ID?

This explains.

If you think your Apple Account has been compromised - Apple Support

With the strong encryption provided on the Apple account, the only way in is if you give someone the Password. That is not hacking, it's probably as a result phishing.

Sorry to be pedantic, but the link from sberman is the way out.

If you didn’t have two-factor authentication enabled and if you did re-use passwords or got phished, it is very likely that the Apple Account is gone permanently.