I'm really pissed right now, so yeah here it goes

I recently made a xbox live account and it was going all fine, i thought outlook could be .co.uk but no, it's .com i realised this today as my xbox wants a "security check" i go to sign in using outlook.co.uk and it says "that email and password didn't work" I super confused, and because I can't sign into freaking live, i cant change the email to another one, this is really frustrating, please help asap