It could be channeling a common fear which is fear of abandonment. Consider if this is possible. It could be fear of the future or dissatisfaction with the current state of affairs. Go back to your memory of the dream to think about what led up to the fiance dying as that is significant. If nothing rings a bell, set it aside, and then, if there is a similar dream, put the two together to see if there is relevance in your day to day life. As during sleep, memories of the day are organized and synthesized into the known. But, the mind is more free to call up matters of consequence but which are attended to during waking time. Your dream might be relevant in context if the whole dream is available and if you can relate it to your current situation.

It may be something inside of you that you have given up or will be giving up; and have nothing to do with your future fiance.

Dreams may be clear as a bell or very opaque.