
Agree with #1. A mental health professional’s reaction to most things (we are taught to do this is school even) is curiosity, not anger. They’d want to address the reason you felt the urge to lie. Worst case would be a more serious conversation about any risks that could have come from the lie, like if you lied about having something you don’t have in order to get medication you don’t need. Or if you did not share a diagnosis, you could’ve been given medication that has bad reactions with it
I hope you can work through what caused you to lie. Just remember the good ol advice to never lie to doctors, same applies to mental health professionals. They are bound under confidentiality and can only share information if you pose a serious threat to yourself or someone else, and even then they only share what’s necessary to the necessary people. Ultimately, they are there to help you. By not giving them information, they have less to work with and can’t do as well of a job