My life is almost perfect. (Could be Triggering)

My life is almost perfect. The reason I started self-harming was because I was always alone, with no one to talk to. It started off as a few scratches with a safety pin (scratching my best friend's initials into my arm). My Mum noticed and told me to stop doing it. One day when I was bored, I asked her if I could phone my best friend. My Mum said,
"Why don't you phone one of your friends, who doesn't make you scratch their initials into your arm?" This made me really mad, because my best friend had been helping me through this, even when I could see she was uncomfortable with me doing this: it was causing her pain. I knew what she had been going through in her life and I didn't want to make it worse. So I went on holiday, trying to stop. I managed to survive a week, but then when I got back, it got worse. My best friend self harms. I don't know whether she still does, but she definitely used to. This made me feel even angrier with myself. She had a reason for why she was so depressed—and I didn't. This helped me stay clean for a few more days.
Two weeks later, my mate came around to my place. I told him that I was cutting myself—thinking I could trust him. He teased me about it, and that triggered me. I cut for most of that day. He doesn't understand how hard it is for me.
The next day my best friend came over. I told her to tell her mum, because I thought it was best to tell a trusted adult about what I've been going through. But I'm still worried about what her reaction was when my best friend told her. I make her mum laugh, these smiles aren't fake.
I was worried about my best friend. It was then that the SI got worse. I unscrewed the blade from a pencil sharpener and sliced that across my skin. One time I cut too deep and it wouldn't stop bleeding.
I've been worried about my dance classes since then: you have to have bear arms, and this girl is going to it from my school and she's not very nice. I hope I'll be able to come up with a good excuse—otherwise I’ll have to try to stop again. There is no reason to harm myself now; I don't know why I do it.