Accidentally deleted my iCloud email address

You may wish to read these articles since some of the things you are saying contradict what Apple says and made offering solutions very difficult. Apple is very specific in its terminology at times and it can be confusing if you use those terms differently.

Create a primary email address for iCloud Mail - Apple Support -“Note: You can’t rename your primary iCloud Mail email address later. If you change your mind, you can add an email alias instead.” (Used to say: "Note: You can’t delete or turn off a primary iCloud Mail address. You can’t use an alias to create a separate Apple ID, and an email alias can’t be converted to a primary iCloud Mail address."

Add and manage email aliases for iCloud Mail on iCloud.com - Apple Support

“Note: You can’t use an alias to create a separate Apple Account.”

Apple used to say:

Note: “You can’t delete or turn off a primary iCloud Mail address. You can’t use an alias to create a separate Apple ID, and an email alias can’t be converted to a primary iCloud Mail address."

Deleted how?

What exactly did you do?

Where are you seeing this replacement?

Aliases don't replace the main iCloud email in any way shape or form.

If you explained exactly what is happening and what you did, someone may be able to advise.

That's not possible. As I said, Aliases can't replace primary email addresses.

If you replaced your primary email address entirely with as different email address, that's not an alias.

Until, and unless you can explain exactly what you did, ad where you are seeing this replacement, its very difficult to offer any help or solution.

The alias is the problem so it’s not too late to fix it,

Try deleting the alias and re-add the iCloud email if it works thank you,