The short answer to this question is mostly yes. Everything you tell me (and other mental health professionals) in session is confidential, exceptin instances where you are an imminent danger to yourself, a danger to someone else, or are expressly unable to care for yourself anymore due to your psychiatric illness. In those circumstances, we are legally obligated to breach confidentiality to protect you or the person you want to harm.
The word imminent, however, is key. For example, a patient can have suicidal thoughts, which in theory implies they pose a danger to themself, without having a plan or intent. This is an incredibly important distinction. This means that just telling me you think about dying will not result in me breaking confidentiality. However, telling me that you thought about killing yourself today and bought something to help you to go through with it would lead me to break confidentiality. The difference is ever so slight, but very important.
(Self.com)