Self harm

I’ve been hurting myself for about 2 years now I’m 16. I don’t really know why I started or what triggered it, but I can’t stop. Every time some thing little happens that makes me upset I just have the urge and I find it hard to fight it off. I can’t talk to anyone because they don’t know how i feel, they don’t get what I’m going through. My dad caught me once and said not to tell my mum and that he would help me it’s been over a year I still do it and he hasn’t spoken a word about it since that day.

I’ve thought about it over and over again about what triggers it, like my school, family friends. I don’t have many because I find it hard to make friends. A lot of the time I’m alone. I want to get help but these reasons seem silly to people who don’t experience it. Help me to please

Ps. Sorry for the long message