(!sorry if I made some mistakes English isn't my first language!/?TW?)

So... I don't know if this is the right place to write this but I need to know what's wrong. So all of this started few months ago (in july or august I'm not sure). It started with a thought that I might be dangerous. I started to have unwanted thoughts about hurting someone (physically and even sexually). It got so bad that I couldn't sleep for 3 days. I also developed some kind of tick I guess (people say that it sounds like a puppy- so...) it's basically that I make weird sounds sometimes. I told my parents about it and they said that they will find me help but now it's getting even worst. I'm scared and I can't say no to these thoughts cuz I'm scared that if I'll say no, they become real. Sometimes I get really angry or sad for really dumb reasons and I feel like I'm the worst person in the world. I was having thoughts about killing myself but I guess I'm over this thoughts. 
I don't know what to think about that. This happened so randomly. I had some unwanted thoughts before but it never got that bad. Well... I don't know why I'm even writing this.