Keep thinking scary thing..

I keep thinking of my arms being cut off, or cut.
I don’t know why, its really scaring me. Im not mad or anything, it just keeps creeping into my head. Im so scared, I don’t know WHY im thinking about it. I don’t want to.
I think im just thinking about it because I know it scares me. I read somewhere that the brain is attracted to fear? I don’t know. Maybe that why im thinking about it.
I know it stupid. I obviously don’t want to literally cut them off.
Then I keep thinking “what if?” like what if the fear actually drives me insane and I actually do cut them off. Im so scared. Every now and then I go “ this is stupid.” And then I calm down for a bit. But then I think about it again, I get scared, and the cycle stats all all over again.
I don’t know what put it into my head. I was on the laptop one night and it just popped up. I felt really uncomftorable about it, (obviously you would) and I was like “just forget about it.” and i did. Then the enxt night it popped up again and I started getting really scared. I was thinking “you’ll forget it in te morning.” But now I keep thinking about it. I just want to forget about it and move on.
And before you say “Go see a therapist” or “go get some help” I cant, im 14. I don’t want to, It sounds really insane.

Im so scared, i just want to forget about it. I guess i just want some kind words or something.

I hope i dont freak anyone out about this. Im literally not an insane person, im not depressed, nor do i want to self harm or have done in the past. i was perfectly fine before this.

Typing it out has actually helped a lot, but i bet i'll be scared about it again tonight.
Its just freaking me out so much. Why am i thinking of it? Is there something wrong with me? Am I just being stupid?