I'm a 16-year-old extreme introvert; I have few friends, and I barely talk to my family. I don't know how to talk to people or how to express my feelings to someone. 

My friend and I were going home after school. He asked, "How did you fail the exam?" I thought that I should tell him about my problems.  

I said, "I have mental illness.".

  He asked, "How do you know that you have mental illness?" (What kind of question is that?).

  I said, "I have been through a depressive condition since 2022. In 2023, when I was in 10th grade, I didn't want to fail the exam, so I cheated, and I got caught and failed my science exam; that was the first exam in which I failed. When my parents came to know that I failed the exam, my mental health got even worse.".  

He didn't even let me finish and said, "What kind of excuse is that? Just say that you don't want to study; I didn't know that you're such a trash person. You don't even try to study. You are dumb or something; you are not an introvert; you just don't want to talk to people. You don't want to be an extrovert."  

What am I supposed to say after that? I never thought he would say something like this to me. He didn't even know what mental illness feels like, and he is judging me.