Dreams involving dead bodies and a setting like a school can be quite unsettling, and it's understandable that you might feel disturbed after such a dream. Here are some possible interpretations:

1. Anxiety and Fear: The presence of dead bodies may symbolize your fears or anxieties about something in your life. It could be related to feelings of helplessness, especially if you were trying to get help but no one listened.
2. Desensitization: Your teacher's nonchalant attitude towards the bodies may reflect feelings of desensitization or apathy you perceive in your environment. This could be related to societal issues or experiences where you feel important matters are being ignored.
3. Change and Transformation: Death in dreams often symbolizes transformation or change. Perhaps there are aspects of your life or your identity that you feel need to be addressed or transformed, but you feel overlooked in this process.
4. Processing Trauma: If you have recently experienced something traumatic or distressing, your subconscious may be processing those emotions through vivid imagery in your dreams.

To find clarity, consider journaling about your feelings related to the dream and any recent experiences that might connect to it. If the imagery continues to bother you, it might be helpful to explore these emotions further, possibly speaking with someone you trust.