I've been having terrible nightmares

[xise]

I find nightmares a blessing, since they are obviously about fear, that much of the interpretation is easy.

The rest is still covered by the veil, but I'd look through common symbols and check their resonance. What concepts you associate with specific people or types of people if they were symbols (such as the sister or Buddhist monks). Some symbols I find are collective though and don't vary, such as females are typically right-brain or feminine energy. May have a deep meditation with the intent to figure it out.

I usually find that loved ones getting killed typically represent a part of me that is killing or warring with the loving concepts inside of me. Usually, a fear is killing them off. But your mileage may vary.

Good luck!