I'm sorry you are feeling this way! These types of things really do suck. Yes these do sound like intrusive thoughts to me. The thing with intrusive thoughts is that everyone gets them, but most people don't really get concerned about them. However, one of the trademarks of OCD is that these thoughts cause anxiety and interfere with your life. I have been diagnosed with OCD and have had similar 'themes' to the ones you spoke about specifically fear of harming others, fear of all kinds of sexual things, and fear of acting out inappropriately, so you are not alone. I'm not saying you definitely have OCD, but in my (limited) experience, you seem to have some of the symptoms of it.

You are correct in that you need to talk to your parents to get professional help. Maybe you could try writing them an email or letter and leave it some place they would see it. Since you were able to write about it here, maybe that will be a more comfortable way for you to communicate with them. You could even print out or show them the post you wrote. When you see a mental health professional, if you are scared (although there is no reason to be scared, it's common and normal) or don't know where to start, you could also show them what you wrote here. Oh and if you ever do seriously feel like killing yourself, please seek help immediately by preferably telling a trusted adult, but also by going to the ER or calling a crisis hotline if you need too.

I hope you get help and start feeling better soon!