Compromised Apple ID

Click on this link "If you think your Apple ID has been compromised" --> https://support.apple.com/HT204145

'Checklist: If you want to see if anyone else has access to your device or accounts' click here --> https://support.apple.com/HT212021

Security and your Apple ID - https://support.apple.com/HT201303

Contact Apple for help with Apple ID account security - https://support.apple.com/HT204169 "This article provides country-specific Apple Support contact information for customers seeking help with their Apple ID password or other security-related issues." Better for directly reporting an issue.

See the information in If you think your Apple ID has been compromised - Apple Support including the following:

If you completed the steps above and think your account might still be compromised, contact Apple Support.

keeps taking me back to input a phone number I don't know

If you have no available trusted devices or numbers, and cannot sign into your account (such as when you have a forgotten password) to add a way to get a verification code, read:

How to use account recovery when you can’t reset your Apple ID password - https://support.apple.com/HT204921

"The fastest and easiest way to reset your password is from an Apple device. Before you start the account recovery waiting period, try to reset your forgotten password on a trusted device. Or borrow a friend or family member’s iPhone, iPad, or iPod touch and use the Find My iPhone app to reset your password. You can even visit an Apple Store and ask to use a device on site."

Contact Apple for help with Apple ID account security - https://support.apple.com/HT204169 "This article provides country-specific Apple Support contact information for customers seeking help with their Apple ID password or other security-related issues."

This is primarily a user-to-user support forum; other Apple users like you.

If you completed the steps above and think your account might still be compromised, contact Apple Support.