Dreams can often reflect our emotions, conflicts, and relationships in our waking life. In your dream, several themes stand out that may help in understanding its meaning.

1. Family Dynamics: The presence of family members, like your dad, sister, and cousin, suggests that your dream may be reflecting feelings about your familial relationships. The argument with your sister and father might symbolize unresolved tensions or feelings of frustration within these relationships.
2. Conflict and Control: Your confrontation with your dad about your sister's behavior and your desire to leave suggest feelings of being trapped or controlled. This could indicate a need for more independence or a desire to stand up for yourself in situations where you feel disrespected.
3. Regret and Consequences: Your father's warnings about regret can signify fears about making decisions that could lead to negative outcomes. This may reflect anxieties about choices in your life, especially regarding family matters or personal desires.
4. Violence and Vulnerability: The shooting in your dream could represent feelings of vulnerability or being attacked in some way, whether emotionally or psychologically. It may also reflect a fear of conflict escalating beyond control.
5. Transformation and Empowerment: The "Winx club fairy transformation scene" could symbolize a desire for change, empowerment, or finding your identity. It indicates that despite conflicts, you may be seeking to rise above them and transform your situation.

Overall, this dream may be communicating a blend of your feelings about family, control, conflict, and personal growth. Consider reflecting on your current relationships and any feelings of frustration or desire for change. It might be helpful to think about how you can assert your needs while navigating family dynamics.