MacBook Pro Admin Login

I am unable to login to my admin profile in setters to unlock/make changes. I am able to login to my admin profile upon starting my computer. I have the correct password - I even reset it to verify. I think the problem is my username itself. When the login window pops up, the username isn't autofilled. I unsuccessfully tried to change my username yesterday, which is when this problem started. Unfortunately, I am unable to log in again to make further changes. Please help!