((((((( KUREHA ))))))))

Sounds more like you are leaning toward a psychotic illness rather than OCD alone. You hold a belief that other people would not normally share (delusion), that you are scared of being infected by AIDS to the point of paranoia and wanting to carry a knife to protect yourself.

Can't diagnose on the internet, I hope you will see a psychiatrist to get a proper diagnosis and treatment. Also continue with your therapist to work on those fears.

Take care.