Dreams like yours can be quite intense and filled with vivid imagery that often reflects our subconscious thoughts, fears, and emotions. Here's a breakdown of some elements in your dream:

1. School Setting: The school represents a place of learning and social interaction but can also symbolize a phase of life where you are experiencing growth and change. It may indicate feelings of vulnerability or pressure.
2. Father and His Girlfriend: Your relationship with your father and his girlfriend could symbolize your feelings about family dynamics and changes in your life. The mention of moving suggests transitions or adjustments that you might be experiencing or fearing.
3. Death and Fear: The recurring theme of death—your dad reassuring you that you won't die, the daydream of corpses, and the presence of your mother's ghost—points to deep-seated fears, possibly about loss or abandonment. It may reflect feelings about mortality or concerns for loved ones.
4. Screaming into the Plushie: This action indicates a need for emotional release or comfort. Plushies often represent childhood innocence and security, suggesting you might be seeking solace from your fears.
5. Intruder and Violence: The presence of an intruder, especially someone familiar, can symbolize feelings of betrayal or fear of harm from those close to you. It may reflect anxieties about safety or trust in your environment.
6. Hospital and Fainting: Being in a hospital signifies a need for healing or a place where you confront your vulnerabilities. Fainting can suggest feeling overwhelmed or losing control.
7. Interaction with Your Mother's Ghost: This poignant moment indicates a longing for connection with your mother and perhaps unresolved feelings regarding her absence. Her refusal to come back may represent acceptance of loss and the reality of moving forward.

Overall, your dream seems to encapsulate feelings of fear, change, and a search for comfort amidst uncertainty. It might be helpful to explore these emotions in your waking life, perhaps by talking with someone you trust or a mental health professional. Journaling about your feelings or engaging in creative expression can also be therapeutic. Remember, dreams can be a way for our minds to process complex feelings, and it's okay to seek support when needed.