Obsolete Apple ID Can't Be Changed

See the instructions below for changing an Apple ID. if you simply change your Apple ID, then you will lose nothing. Note that you are using an Apple ID right now unless you signed in here using someone else's.

Change your Apple ID  https://support.apple.com/en-us/HT202667 Read these two sections very carefully to see what is allowed under your circumstances: If your Apple ID is a third-party email address and How to change your Apple ID if it ends with @icloud.com, @me.com, or @mac.com.

Before changing your Apple ID using a computer, sign out of all Apple services that use your Apple ID. If you are going to use an iPhone, iPad, or iPod, then stay signed in with your Apple ID on only that device. This instruction is taken from the above document under the heading Before you change your Apple ID.

For sign out purposes, see Where can I use my Apple ID? https://support.apple.com/en-us/HT202659 “This list is provided for informational purposes only and is subject to change without notice. It's not intended to include every feature or service that uses Apple ID. Visit the Apple ID support page for more information.”

And see What to do after you change your Apple ID or password 

 https://support.apple.com/en-us/HT204071

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If If you decide you want to create a new Apple ID, see:  How to create a new Apple https://support.apple.com/en-us/HT204316See See the data implications below.

Some of these things will apply to your situation even if you are not changing your Apple ID: What to do after you change your Apple ID or password https://support.apple.com/en-us/HT204071

 Keep in mind that some things available under a first Apple ID will not be available under a new Apple ID. For example, you won’t be able to transfer anything purchased from the App and iTunes Stores to the new ID. And, there are other issues to be addressed. See

what Eric Root say on this matter here:  https://discussions.apple.com/thread/251263630

what Winston Churchill says about it here: https://discussions.apple.com/thread/7452747

You also set up family sharing between the IDs to share purchases made with them. See:

Family Sharing  https://support.apple.com/en-us/HT201060

Set up Family Sharing https://support.apple.com/en-us/HT201088

Call apple support. I worked at apple support for about 9 months with the first 6 were strictly apple id security. If memory serves there are things they can do to assist (only accessible from their side). To be upfront there were a number of times where I was unable to help someone regain access because they had a deleted hotmail account or forgot their email password or could not answer security questions, etc. It is possible to be so locked out that even apple cannot help.