sign in

this is mobile minecraft problem but I tried signing in by my number then it didn't work and It connected to a old email I don't have access to and now it won't get off my screen and now only the "Cancel" button works and nothing else. I do now have a account made but i'm going to sign in by my email I have access to and not a number but I just need help getting off the sign in screen and signing in again is all I want.