Yes, a female employee may enter a men's restroom during store hours. Generally the employee would knock first, but in a case of an emergency and for the safety of the patrons she may enter without knocking. As for emotional distress- forget it. The action has to be intentional- specifically directed towards you, and the behavior must be of the type to be outrageous to the general public. No cause of action here.
No, you cannot sue. This is not a civil rights violation.
You won't be able to claim damages for emotional distress.
Frank W. Chen is licensed to practice law in the State of California. The information presented here is general in nature and is not intended, nor should be construed, as legal advice. This posting does not create any attorney-client relationship with the author. For specific advice about your particular situation, consult your own attorney.