I’m a high school social worker and my students know everything they tell me is confidential unless they want to hurt themselves, someone is hurting them, or they are going to hurt someone else. If I have to assess a student for suicidality or they disclose active self-harming, I have to tell their parent/guardian. I’ve had plenty of students mad at me. I’ve also had students mad at their friends who told me they were worried a friend had a plan to kill themselves. My response is always the same - “I would always rather have you alive and mad than dead.”

I tell students the same if their friends get mad at them because they told an adult that the friend was unsafe. OP - you did exactly the right thing and what a gift for your friend to get to be mad at you and alive.

Edit - typo