Cannot create or login to iCloud Mail app. please help, completely frustrated

Mail toggle at APPS USING ICLOUD ALSO NOT SHOWING.

Nothing happens when i press Enable iCloud Mail here:

When manually entering the AppleID and password, the screen gets stuck with signing in animation:

I’ve tried restating my phone, tried sign-out and sign-in. Nothing works!

I have created a custom email id from iCloud+ as well, which now I cannot access its inbox.