Is self-harm unforgivable?

I had my first arm cut on New Year's Day as a sixth grader.
I felt like a sandstorm was flowing through my head and my field of vision was dark, and I was hurt because I couldn't think about it properly.
On the verge of getting hurt, I first thought “I want to die,” and then made up excuses saying “I don't want to die” and “if I get hurt, I'll make amends until now.” I just skated for the first time, but at that point I began to think, “There is no way that doing something like this would be redemptive; rather, they are committing a series of crimes.” However, I told myself, “I don't like being half-hearted, until blood comes out anyway,” “if you cut it, you'll be rewarded,” and “was this how painful it was until now,” and I cut it off over and over again. Along the way, the thought “if a scar remains, everyone will acknowledge what I have endured until now” came to mind, and I became a little happy, and I became afraid of myself. I was impatient when I saw blood. I felt like there was no going back.
I couldn't stand it, and I immediately confessed my behavior to my mother. It was meant to be a confession. My mother blamed her own mother. And then he scolded me. I promised my mom that day I'd never do it again.
However, now that I'm in the first year of junior high school, I was hurt again. I felt uneasy about my first wound getting thinner and said, “I've endured it until now, and even though I've worked hard, I can't be recognized. That's because I thought, “I only pay attention to my older sister, and if I cut it off, they'll look at me again.” There's nothing wrong with my sister. I let go of my sister by myself. When everyone opened their mouths, the first word was my sister, and I felt lonely because they didn't even talk about me.
From that day on, it was probably cut a hundred or dozens of times, and most of them remained as indelible wounds.
One day, while searching the internet, I saw that it was described as a mortal sin to “injure the Buddha's body.”
I said, “I've heard that people become Buddhas after death. Then I thought, “Now that I'm alive, hurting my own body is also a mortal sin,” and impatience, anxiety, fear, and regret rushed in.
Then, I decided to write it here because I wanted to hear a Buddhist story about self-harm.

I also feel guilty that the day I cut for the first time was New Year's Day. There was no reason I chose New Year's Day, and I happened to run out of patience on that day.
We haven't had Amka since New Year's Day this year. However, I overdosed on psychosomatic medicine.
I wanted my family and teachers to understand my pain even if I wasn't worried.
Will I end up in hell after death like this? Have you done something unforgivable?