Q: I can't reset my security questions. Advice?

Help here >    If you forgot the answers to your Apple ID security questions - Apple Support

If nothing there works for you, contact Apple Support.

You contacted Apple directly?

If your Apple ID is locked >  If your Apple ID is locked - Apple Support

Apple ID security issues -

Account security issues almost always require you to speak directly to an Apple representative to securely establish your identity as the account holder. You can set it up so that Apple calls you, either immediately or at a time convenient to you.

1. Go to http://www.apple.com/support/appleid/

2. Choose Contact Support and click Contact Support

3. Choose Other Apple ID Topics and choose the appropriate topic for your issue (Security questions or password)

4. Choose, No Thanks, Continue

5. Choose the best method for you for contacting Apple

Late 2012 Mac mini, macOS ?;  Watch, 38 mm silver AL, watchOS 3; iPad Air 2 & iPhone 6+, iOS 10.0.1;  Apple Airport Express