Wrong email on iCloud and can't access it to change password

Hi all

just recently I upgraded to a Mac book pro and also iPhone 6s. During my last phone contract (2 yr period) my email got hacked and so changed my email address. I of course change my email accounts with all my stuff, though my iPhone seem to keep my old email and I couldn't delete. It was never really an issue as everything still functioned though when I tried to import into my new phone the cloud activated (which I've never used) and stopped upload.

As the old email account got deleted I can't change my password and I also can't turned off search for my iPhone in settings due to needing the password. Also I have just tried to log into my laptop and it won't let me.

I actsully have a booked call with Apple support tomorrow though thought Id also try here as I'm really struggling

any help welcome, thanks in advance

Dominic