I can't stop thinking about being kidnapped and raped, am i mentally ill or what?

May be depressed: If you have no objective reason to be worried about this and have not been a victim in the past, then you may be depressed. You should discuss this with a doctor or mental health professional. And if you have been a victim, you may be experiencing post-traumatic stress disorder, and should see someone for that reason.

Also possble OCD: No individual opinion, but if not recurrent and intrusive thoughts that can follow a traumatic event such as described, then unwanted and intrusive thoughts if they interfere with focus, daily functinioning, work, relationships or general health and well being could be related to obsessive-compulsive disorder. If this is interfering consult a competent psychiatrist or clinical psychologist.