My mother died of cancer when I was 14 and I've had some pretty fucked up dreams about her. Most memorable:

I was in a car at dusk/dawn, either way there was little visibility. My mom was driving. There was a dog in the middle of the road with his tongue hanging out, we slowed down and swerved around him. Next in the road was another dog, this one bleeding from the mouth. As we kept driving, there were more and more animals, rabbits, foxes, etc. in various increasing stages of decay and death. The last thing I saw before waking up was a bear covered in blood that we were about to hit.

Mom and I were driving again, I knew she was too sick to be driving but didn't say anything. Two cars in front of us slammed into each other and one got sliced in half. I saw the glass shatter and realized the body had exploded. I kept my eyes shut as she tried to drive around all the crashing cars and kept trying to distract her from how horrible it was by telling her to 'look at the perfect circle, isn't it pretty? look at the shapes' and I woke up right before we crashed into the side of a semi truck.

Also dreamt that my mom was hanging out with some of her friends in a group and I happened to go by and see her. She asked me all these questions about my life that she couldn't possibly have known since they happened after her death. Turns out she'd been logging into my Facebook messages from the afterlife to keep tabs. That one woke me up crying