Kinda hard to explain

See if anything here helps.

iMessage on your iPhone or online - Deregister. 

Messages or FaceTime - Add or remove your phone number    

Why don't you try to recover your old account?

See the Apple Support article(s) below. 

If your Apple ID is locked or disabled - Apple Support.    

If you have changed your ID or password, have you followed the steps in this article?

What to do after you change your Apple ID or password - Apple Support.      

If necessary, contact Apple ID Support for assistance.  See the Apple Support articles below for contact information.  

Apple ID - Official Apple Support.    

Contact Apple for help with Apple ID account security - Apple Support.   (Link doesn’t always load)  

Get Support          Work through the screens to get a chat option. You may have to pick a slightly different problem.

Apple Support schedule phone call

If necessary, try Twitter

https://twitter.com/AppleSupport.          

From the Apple Support article below. 

Without proof of your identity via security questions and other carefully selected criteria, Apple Support can't help you reset a password or perform any other actions on your account. These policies are audited and reviewed on a regular basis.

Security and your Apple ID - Apple Support.      

1)Just try to change trusted phone number on "Settings/Apple ID/Password & Security".

2) Try to change "My number" through "Settings/Phone".

3) If first two steps won't work, reset all settings through "Settings/General/Reset".

Important note: Reset all settings will reset your wallpaper on home screen, network settings, keyboard and accessibility settings, FaceTime & iMessage activation, Touch ID/Face ID & Passcode, sound and haptic settings etc.