We don’t have sufficient information to reset your security questions

See If you forgot the answers to your Apple ID security questions https://support.apple.com/en-us/HT201485

By saying "we don’t have sufficient information to reset your security questions," Apple has notified you that you can't answer your security question satisfactorily. So see Security and your Apple ID https://support.apple.com/en-us/HT201303

This document says “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.”

Thus, given Apple's notification, we can do nothing to help you, except to mention that Apple support might help you if you have an extenuating circumstance (e.g., you have your receipt for your purchase of a pertinent device from an authorized Apple seller with its serial number on it). If you want to contact Apple Support to discuss any possible extenuating circumstance, see the support options below. Alternatively, if an Apple Store is open in your area, then you can go there to deal with your extenuating circumstance. You also can make a genius-bar appointment (https://www.apple.com/retail/geniusbar/) if you want.

Get a call from Apple support to help solve your problem using this link https://getsupport.apple.com/?caller=kbase&PGF=PGF63005&category_id=SC0245&symptom_id=23362

Apple ID Support https://support.apple.com/apple-id

Apple ID account security for country-specific and region-specific help https://support.apple.com/en-us/HT204169

Get Support: We’re here to help https://getsupport.apple.com/. Go through the options to find the best support option.

If it has died and it is under warrant (even under AppleCare), contact Apple Support:

Get a call from Apple support to help solve your problem using this link https://getsupport.apple.com/?caller=kbase&PGF=PGF63005&category_id=SC0245&symptom_id=23362

Apple ID Support https://support.apple.com/apple-id

Apple ID account security for country-specific and region-specific help https://support.apple.com/en-us/HT204169

Get Support: We’re here to help https://getsupport.apple.com/. Go through the options to find the best support option.

Did you contact Apple Support? If so, what did they say? If necessary,

Apple ID - create a new.      

Apple ID – Create         

When changing to the new ID, there may be some data loss, but you can minimize it. Messages conversations will be lost if they are addressed to the ID. See the article below for other places that the old ID should be removed. See Winston Churchill's response in the below discussion. Also try to set up Family Sharing to keep access to your apps/purchases. 

How to switch Apple IDs on your iPhone or iPad.      

How to transfer all files from one iCloud account to another.        

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

Family Sharing.         

Family Sharing - Set up.       

Are you seeing activation lock? If yes, post back. Note that sometimes Apple Support can help you with activation lock. But, if (1) you, or the person you acquired your device from, doesn't have original purchase receipt for your device with the device’s serial number on it; (2) you didn't inherit the device, or (3) you can't obtain the needed password from the person you acquired the device from, then the device is useless to you.

If necessary, try Twitter to establish initial contact.

https://twitter.com/AppleSupport.          People have posted it may take an hour or more to get a response.