You will have to contact Apple support. I am not sure there is a solution to your situation. If someone has hacked your AppleID password, and has access to one your own trusted devices to get an AppleID 2FA code and thus sign into a device as you, then they can alter your recovery code. Or if they had one of your trusted devices in their hands and knew your password they could do so.
How did someone both get ahold of your AppleID password and one of your devices to receive a 2FA code or use?
Since using a recovery key means the automated account recovery process is no longer possible, you may be unable to recovery your account.
Contact Apple support. At the least, they may be able to disable or delete your account for you.