I agree with Lynn. If they are intrusive thought that u know don't make sense, then it could be OCD. If u enjoy these thoughts and have malicious intentions, then that is an issue. Either way, it sounds like the thoughts are interfering in your life and I suggest seeing someone about it. Talk to a counselor at school, an adult, anyone. Sometime it takes an adult to get your 'rents to see it. Medication and therapy are both effective treatments...