Dreams can often reflect our subconscious thoughts, feelings, and fears. In your dream, the dim cabin may symbolize a private or isolated aspect of your life or relationship, suggesting a sense of intimacy but also potentially uncertainty or a lack of clarity.

Your boyfriend's transformation into having "huge watery fish eyes" could represent a feeling of vulnerability or fear regarding his emotional state or health. The eyes might symbolize how you perceive his feelings or perhaps a fear that he is unaware of something significant that could affect your relationship.

Feeling scared and thinking you need to go to the hospital indicates a sense of urgency and concern for his well-being. This could reflect your protective instincts towards him or worries about issues in your relationship that need to be addressed.

Overall, this dream may be urging you to communicate openly with your boyfriend about any underlying concerns you have. It might be helpful to discuss your feelings and ensure both of you are on the same page emotionally.