Help me understand these dreams I've been having since I was little?

I've been having these same dreams since I was very little. I find I have them mostly after a family fight or even get-togethers we have throughout the year, even if I had a good time.

These dreams are all different, but have the same concept: My family abandoning me because they don't want to die or get hurt themselves. I can recall having these dreams often, but can't remember them, or at least the important details.

I can remember the first dream like this and the latest the best, though.

When I was little, (3-5 years old), I had this dream: Me, my mom and my grandfather were at my grandparents house and we heard a sound coming from the hallway, (which isn't surprising because I was always terrified to go down it), and a gnome-like thing came out. They got rid of it and it froze, not in ice, it just stayed still, and put it in the kitchen. This happened 11 times, and they told me on the 12th time "we" would hide. When it did, they hid and I didn't, leaving me exposed. I immediately woke up before anything happened, though.

In my more recent one, we slept out in a place where someone was murdered. There was a pulley system with buckets for carrying water in the center which, doesn't make sense in the "real world", but the murderer came up through there to kill someone sleeping in the green chair. (Don't ask, it was a dream). I don't know why, but everyone was thinking that he was going to come back, so my aunt made me sleep in the same green chair, and right at the foot of it was the pulley system. When she decided to change spots, we slept out on the balcony. It still doesn't make any sense to me why. But there was no railing, leaving about a 100 foot fall to the ground. When I said "What if someone falls off?" she takes the same chair and puts it right next to the edge, smirking at me. I ran off and my mom and grandma chased me, before they caught me, I woke up.

Does anyone have any idea what causes these dreams? I've only had one traumatic experience in my life: I watched my grandfather (the same one mentioned up there) die. It was unexpected and I saw my grandma performing CPR, which, being only almost 10, terrified me. Then the doctors, ambulance workers, and everyone thought I was involved somehow in his death and I was questioned. A few days later, I found the dead body of my long-time friend, my dog. (It may not seem like to big of a deal, but for me it was). The dreams have gotten worse since then, but started long before this.

Thank you to anyone who can make sense of this, and who kept up reading the whole thing without getting fed up. :)