This dream is rich with symbolism and emotional undertones, suggesting a complex interplay of relationships, responsibilities, and personal fears.

1. Living with Parents: This could symbolize a return to childhood or a desire for comfort and security. It may reflect current feelings about your family dynamics or a longing for the simplicity of those early years.
2. The Mansion: A large, strange mansion often represents the self or the mind. The vastness and maze-like quality could indicate feelings of being overwhelmed or lost in your thoughts or emotions. The presence of a guest house might symbolize a desire for personal space or independence.
3. The Toddler: The toddler's attachment to you may signify a sense of responsibility or nurturing instincts. Losing the toddler could reflect anxieties about neglecting responsibilities or fears of losing innocence or purity.
4. Bathing and Drowning: The act of putting the child in the bathtub can symbolize a desire to cleanse or protect. The drowning incident might represent feelings of being overwhelmed by emotions or situations in your life that you feel unprepared to handle.
5. Conflict with Your Sister: The argument about cleaning up the mess indicates possible tensions or unresolved issues in your relationships, especially with your sister. This could reflect a sense of being burdened by familial expectations or a desire for recognition of your contributions.
6. The Guest House and Maze: This aspect of the dream suggests a journey of self-discovery or exploration. The maze-like nature could indicate confusion about your current path or struggle to find your place.
7. Possession and Burning: Your father being possessed symbolizes a conflict between your familial ties and your individuality. The burning could represent a painful transformation or sacrifice you feel is necessary in your life. It might also indicate fear of losing a loved one or a part of yourself.
8. The Cemetery and Breaking the Code: This part of the dream could signify a confrontation with past issues or unresolved emotions. The struggle to break the code may represent the effort to understand or reconcile those feelings.
9. The Reunion of Ghosts: The resolution with the ghost signifies closure or the release of lingering attachments, but the death of your father indicates a fear of loss, particularly in terms of guidance or support.

Overall, this dream might be urging you to confront your fears about responsibilities, familial relationships, and the transitions you are experiencing in life. It suggests a need for self-exploration and perhaps the importance of establishing boundaries while navigating complex emotional landscapes. Reflecting on your feelings toward family and your own personal journey may provide further insights.