Masturbation and thoughts

I have a problem where I have sexual fantasies with a fictional character and then feel the urge to masturbate. But there are two things that bother me with it.
First of all, the sexual thoughts themselves. Since I was young I had sexual thoughts (even as a young child) and it bothers me now. I have never been sexually abused, never assaulted or anything remotely similar. I never saw my parents having sex. But still somehow I had those sexual thoughts and they never bothered me as a child (welp now they do). I would understand if it started with Idk 12 since I started reading fanfics and I'm not even surprised that I'm really interested in sex as a 16 year old (it's usually a taboo thing but I think I really yearn for that intimacy with someone because it gets so glorified) but why with 8?? It makes me worry that something was done to me and that I deleted it from my brain. And even now I feel so ashamed of having sexual thoughts because I have them all the time. I tried to like not have any sexual thoughts but they keep coming and honestly it's like a coping mechanism to me.
Another problem is the shame and disgust I feel for masturbating. Honestly it just lasts some mere seconds and I don't need to watch anything to do it; I have the sexual thoughts or just remember slightly how I felt during masturbation and then I want to do it. But everytime I'm done I feel disgusting and so ashamed of myself even though I know it's normal and healthy. It's like I can't go without a week of not doing it/thinking about it. I got so paranoid at one point that I thought there were hidden cameras and I was scared that it would be somehow get public to the point where I made a plan of killing myself. How do I get over the shame and anxiety by masturbating?

Hello and welcome.

You might have just been precocious- I truly feel sorry for people growing up in the 21st Century, full of sex everywhere and the internet. I didn't have such issues. That alone is enough to explain your early preoccupation.

The age you're at, if I read it correctly- well, a teenager who doesn't think about sex has to be a rarity. That's just kinda what they do.

As far as the shame and disgust go, I remember having a lot of that also as a teenager. Being a teenager is not easy. I think you'll learn to live with the feelings, and gain a sense of perspective that you don't currently have. But those things only come as a person ages. Things that drive you to tears now, will seem not nearly so important in five years. For all of us, growing up is something that we have to just ride out until we get to the other side. As an adult, well, I can think of far worse situations to be in. You're not in trouble. You don't have an STD. No one is pregnant. No one has been victimised by a sexual predator. Looked at it from that way, you're doing pretty good. What seems so all-encompassing now, will seem less so with the passage of time.