Problem_Changing Admin Account_after moving country permanantely_ Macbook Pro

Problem_Changing Admin Account_after moving country permanantely

I moved from the UK to another country, in the EU . Since then, I’ve been experiencing massive  problems with my account, and using all functions and Apps properly. I’m  having trouble changing or creating a new UK Apple account according to the country I live now, and where I want to use my Macbook.

Despite various approaches to solutions, it seemingly remains an unsolvable problem.

I already changed the country and language in the system settings.

I already changed the Account information, email address and phone number, language, country and address in system settings to the new country. 

I am unable to create a new account. Subsequently, I am restricted to use all functions, Apps, web applications, etc. accordingly.

I already followed numerous  advices, generated from web research, again and again without success.No matter what, in the end I always had an “Error” message  displayed with no further explanation or alternative option  After half a year, I gave up.

Current , persisting Account Problem Status:

After various attempts to change my account ,I now have an additional  problem that I can't log in to any of the accounts, not with the original admin account ID, nor  establishing, or adding , a new account with the new email address and new phone number to generate a new Apple Account ID. I am unable to use the original login address since I moved country,for a few years  now, as I  don't have access to the original UK phone number and no longer have the UK mobile phone , neither the original account address.  

Subsequently, I can’t verify my identity. It’s a vicious circle ……  

Currently , I am using a new mobile phone , bought in the country where  I live .

 I wrote down all the passwords and help. And if I want to reset the password via Apple ID, it simply doesn't work! (Password shakes) even though it is the correct password.

 Can someone help me, please?!

Any targeted, clear answers, practical advice that can be implemented advice - tailored to my specific problems -  would be helpful, to find a way out  out of this labyrinth , always following the wrong paths. My goal is,  to be able to use all Apple functions and services, web application ,apps, etc. again, in accordance with the terms of use in my country !!!

Thank you in advance for your help.