I am not very good at interpreting dreams but wanted to welcome you to psychcentral.

You mention you had many nightmares before you divorced. I would presume you were under a lot of stress as that relationship floundered. You have also been under a lot of stress recently while they try to diagnose your recent illness. Perhaps if you can get a diagnosis and some treatment your nightmares would lessen.

Have you ever talked to a T (therapist)? Most people find that somewhat helpful.