It is general assumption is that you can’t delete your Apple ID.
Even if you send support or help request to Apple Support team even they will say that…
But here is way out of this goof-up.
First step is to gather all required information to varify your account in one place..
First is Your ‘Username’
Note it down
Second is Your ‘Security Question’s Answer’
Note it down it too…
Third is to be ready to login with your account
Under security tab you have ‘Generate Pin’ tab… You will need this tabbed to be click to generate pin to share with your Apple iTunes Support Team expert which will help him to access your account & confirm your identity.