The meaning of theis dream/nightmare? Why did I dream this?

never have nightmares. I am not easily scared either. So a few nights ago I had this really strange dream I don't remember the whole thing exactly, but here you go:

The setting was in some sort of house. It was very eerie. The air felt heavy and it was dark. The only light i remember was faint and reddish (like a room with all the lights off and barley any sunlight coming through behind a dark red curtain). I remember everything looking old and rusted. The floor was some kind of rusted metal.

I was waking slowly . I walked up to an old chest that was in the middle of the room I had entered. It had a pocket knife, like knife on it. It looked like there was some type of liquid on it, blood was the first thing I thought of. I picked it up and put it to my wrist and screamed in a sort of discomfort, fear, and pain . I remember seeing my hand and it was very pale, and almost grayish skin tone. I didn't cut myself, put the knife down, and walked away,, entering another room. I don't really remember anything that happened after that. The other room was basically the same but smaller, and I remember looking at a picture on the wall. I forget what it was though.

When I woke up, it was morning and there was light outside. I was walking around my house feeling as if I was being followed or watched by somebody. I felt very uneasy. There was nobody else in my dream, it was just me, alone.

So I was wondering, what could have this dream possibly meant? I never have nightmares, but in this dream, it felt like a nightmare, for some odd reason. I really felt like I needed to have a logical explanation for this because it has been making me feel very, different every since it happened. Thanks for your answers.

Addition things, unrelated to dream:
Im a 13 year old girl. My mother passed away about a year and a half ago. I was home alone when I saw her have the heart attack that killed her. After her death I was really depressed. I have thought about suicide, but I never attempted it mostly because I feel that I have to take care of my dad and my younger sister and I would be too afraid to kill myself. Before my mother died, when she got upset or depressed, I would see her with a knife to her wrist moving it back and forth. Me and her both knew she wouldn't do that to herself but she tried to show me her pain. Overall, I am a happy person. I have learned to accept the fact she has moved on to places unknown, that is why this dream was unexpected and weird to me.

Im sorry if that was a lot. I just felt like that could possibly have something to do with it. Thanks again.

-kelly