Hi, I'mCustomer Welcome to JustAnswer. I'm reviewing your question now, and will post back with your reply ASAP.
What is the version of your Mac OS please?
If you still cannot login :
Move the mouse pointer to the menubar at the very top of the screen, click "Utilities” and then select "Terminal" from the dropdown.
Let me know the results please
Has everything worked out please?
Do you still need help?