Can't add my account again

I would recommend a Factory reset. Remember to choose to keep games and apps, if you don't want to re-download/install anything. Then try adding your account again.

1. Press the Xbox button to open the guide.
2. Select Profile & system > Settings > System > Console info.
3. Select Reset console.
4. On the Reset your console? screen, you'll see three options:
   • Reset and remove everything. This option resets the console to factory settings. All user data, including accounts, saved games, settings, home Xbox associations, and all games and apps will be deleted. Use this option when selling
     or gifting the console, or as a last resort in some troubleshooting cases.
   • Reset and keep my games & apps. Use this option as your primary choice when troubleshooting. It will reset the OS and delete all potentially corrupted data without deleting your games or apps. In some cases, if a corrupt game file
     is causing the issue you're troubleshooting, you may have to choose Reset and remove everything, but you should always start with Reset and keep my games & apps.
   • Cancel. To back out of this screen, simply select the Cancel button. No action has been taken at this point. This is a safe exit from this screen.

After you select one of the options, your Xbox One console will begin the process of erasing the selected content and resetting itself to the default settings.

After I press add new it just loads and takes me back to the same screen

Ok. How far do you get in the process when adding to the Xbox ?

1. Press the Xbox button to open the guide.
2. Select Profile & System > Add or switch > Add new.
3. Enter the email address for the Microsoft account that you want to add, and then select Enter.
   Important Make sure that you do not select Get a new account, unless that’s what you want to do. If you select this, you will create a brand-new Microsoft account.
   
4. Enter the password for your Microsoft account that you want to add, and then select Enter.
5. Read the Microsoft Service Agreement and Privacy Statement, and then select I Accept.
6. Follow the steps to configure your Sign-In & Security preferences to add your Microsoft account to your Xbox One console.

I did so and I still can't add my account... It's just loading and takes me back it's not giving me further options to add in my details

I can log on @account.microsoft.com but I can't add the account on my console