Dreams involving attacks, particularly by animals like a black wolf, can be quite intense and frightening. Here are some interpretations and insights into your dream:

1. Fear and Anxiety: The wolf may symbolize a fear or anxiety that you are currently experiencing in your waking life. It could represent a situation or person that you feel threatened by, or feelings of vulnerability that you are struggling to confront.
2. Feeling Powerless: Your inability to scream or move can signify feelings of powerlessness or being trapped in a situation. This may suggest that there are aspects of your life where you feel you lack control or agency.
3. Shadow Self: The black wolf could also represent your "shadow self," which encompasses the parts of yourself that you may not fully accept or acknowledge. This dream might be urging you to confront these hidden aspects.
4. Transformation and Change: Wolves are often seen as symbols of transformation and instincts. If you are going through a significant change or transition, this dream could be reflecting the internal struggle associated with that process.
5. Call for Help: The act of trying to scream for help indicates a need for support or assistance in your waking life. It may be beneficial to reach out to friends, family, or professionals if you're feeling overwhelmed.

Consider reflecting on any current stressors or challenges you're facing in your life. Journaling about your feelings or discussing your experiences with someone you trust may help you process the emotions tied to this dream.