I started a supply post in September, and to be honest, its not gone very well. I was really enthusiastic at the beginning, but I got a bad observation a few weeks in. My HoD has been supportive, and I had another observation, which she said was a good lesson. This made me feel better. I do like the school, and the students are generally good. The other staff are nice too. However, things have gone wrong again this week. I have a class with a child in whose behaviour isn't great - he's ADHD and struggles. I got an email from a parent complaining about this child and how it was disrupting her son's learning, and I responded by telling her that the other child has ADHD and can't always help it, but I follow behaviour policies. I was told by the HoY of that year today that the parent had called her complaining, saying that I'd told her that the other child couldn't help it because of his ADHD, and I'd not given her a satisfactory answer. The HoY said she was annoyed with the parent, but also that I shouldn't have told her about the other child's condition, as its disclosing confidential information. The HoY said she'd deal with it, but I might have to be asked about data protection. I feel like walking out. What should I do?