unable to verify account name or password

hi, so i'm trying to restart my macbook air but i keep getting this message that the system is not letting me and its unable to verify my account name or password. i have a hunch that this is because i deleted one of my internet accounts. the account was my high school email that i lost access to shortly after entering college. i have no way of logging into that email again because i think its now void. i need some help with this.